PollTrack will periodically re-post this tutorial to accommodate new visitors:

For new visitors or for old visitors who would like a refresher course, here is a guide to PollTrack's unique mapping system. Remember, both Today's Map and Tomorrow's Map will be changing continuously throughout Election 2012, so check back often.

First, an overview: our innovative presidential election maps offer a snapshot of where things stand and where they are headed in the state-by-state hunt for electoral votes. Armed with public opinion polls, the history and demographics of each state, knowledge of the nation’s geographic and cultural diversity, and common sense and intuition, political director Maurice Berger offers continuous updates and a blog (below map) on the state of the presidential race. Today’s Map Today monitors its current status. Tomorrow’s Map Today charts its momentum in the coming days or weeks. And Election Day Today records the actual outcome of the 2012 presidential race.

Here's a guide to each map:

Today's Map Today: This map monitors the current status of the race. It gauges the relative strength of each candidate within each state as it presently stands. Each state is marked with its abbreviation and number of electoral votes. Click on a state for commentary in the ongoing PollTrack blog.

States are called on an ongoing basis: Blue and Red for “Safe” Democrat or Republican respectively, Light Blue or Light Red for states currently “leaning” toward one party or another. Determinations are based on a combination of factors, including poll averages, trends in most recent polling that contradict or call into question the accuracy of these averages, and on the ground reports and information. For diehard red or blue states (like Idaho or DC), little polling may be available, so the state will be called on the basis of on the ground reports and/or its stable voting history.

Tomorrow's Map Today: This map charts the momentum of the race. It tracks the hunt for electoral votes in each state as it might play out in the coming days or even weeks. States are called on an ongoing basis: Blue and Red for trends that suggest “Safe” Democrat or Republican respectively, Light Blue or Light Red for trends that suggest a state is “leaning” toward one party or another. Determinations are based on a combination of factors, including movement in the most recent polling, a state’s demographics and voting history, on the ground reports and information, and news about a candidate's state-wide political activities.

Election Day Map Today: This map forecasts the outcome of the 2012 presidential race. Win Democrat or Win Republican respectively. Determinations are based on a combination of factors, including long term and recent trends in state-wide polling, a state’s demographics and voting history in relationship to these trends, on the ground reports and information, and news about a candidate's state-wide political activities. States are called on an ongoing basis, with Blue (Democrat) and Red (Republican) indicating PollTrack’s long-term prediction for a state. NOTE: calls are made only when voter opinion begins to solidify in each state, thus this map will fill-in slowly over the next two and half months.

While President Obama's lead in Nevada has narrowed since June--according to a new survey by Public Policy Polling Obama leads Romney by +3%, 50% to 47%--PollTrack continues to rate the state Leaning Democratic on Today's Map due to the president's all important reaching of the 50% mark.

Voters have a mixed view of Rep. Paul Ryan, Mitt Romney's VP pick. According to a new Gallup poll, 38% say their opinion is favorable, and 36% saying it is unfavorable.With a sizable portion of the electorate undecided in their view of Romney, there may be room for his overall numbers to rise after yesterday's convention speech and the national exposure it provides. Still, the candidate's overall favorable number is relatively low for a VP candidate.

A new Mason-Dixon poll in Missouri reports that Mitt Romney leads President Obama, 50% to 43%. While other polls have shown an even closer race, PollTrack continues to rate the state Leaning Republican on Today's Map.

A new survey by the Philadelphia Inquirer in Pennsylvania reports that President Obama now holds a significant +9% lead over Mitt Romney--51% to 42%. PollTrack moves the state on Tomorrow's Map from Leaning Democratic to Democratic. 

Another poll just released, by the Tarrance Group, reports that President Obama is locked in a very close race nationally with Mitt Romney. The President leads by just one point in the poll, 47% to 46%, with 7% undecided.

While a  new Associated Press/GfK poll reports that President Obama is only +1% ahead of Mitt Romney nationally--47% to 46%--it also shows a more significant gap when people were asked who they thought would win: 58% of adults said Obama to be re-elected, while just 32% said Romney.The expectation of a win is often important in a close election, dampening support for the candidate who is thought to have a lesser chance of winning. PollTrack will continue to track both the national numbers as well as voter expectations.

The one possible vice-presidential bounce for Mitt Romney may be evident in Rep. Paul Ryan's home state of Wisconsin. A new Marquette Law School poll reports that President Obama leads Mitt in Wisconsin by three points, 49% to 46%. An earlier poll by Marquette had the president up by +5%. Several other polls in the state over the past week report a similar improvement in Romney's numbers. PollTrack moves the state on Today's Map from leaning Democratic to Too-Close-To-Call.

According to Gallup, "three months before the election, President Barack Obama gets good marks from Americans for his handling of terrorism, fair marks for education and foreign affairs, but poor marks on immigration and three big economic issues: the federal budget deficit, creating jobs, and the economy generally." Here is Gallup's chart:

A new poll by Mitchell Research in Michigan reports that President Obama continues to lead Mitt Romney by five points, 49% to 44%. PollTrack moves the state on Today's Map from Too-Close-To Call to  Leaning Democratic.

Despite the addition of Wisconsin US Rep. Paul Ryan to the GOP ticket, A new CNN/Opinion Research survey in Wisconsin shows President Obama still leading Mitt Romney, 49% to 45%. PollTrack rates the rate on Today's Map Leaning Democratic.

PollTrack's US Senate Race Chart will be coming soon. With PollTrack's outstanding track record on predicting the outcome of US Senate races--and the potential of a very close overall race for control of the Senate--this year's chart should be very exciting.

A new poll by Franklin & Marshall College reports that President Obama now leads Mitt Romney in Pennsylvania by six points, 44% to 38%. These numbers actually show a gain of +6% for the GOP challenger; Obama led by 12 points in the poll in June.

In numbers that cannot be positive for the president's reelection effort, A new poll by CNN/Opinion Research reports that optimism about how things are going in the country now at 36% -- down from 7% in April; 63% say that things are going poorly.

In another sign that the Romney campaign may be in trouble, a new poll by SurveyUSA in Missouri (taken before Paul Ryan was aded to the GOP ticket) reports a virtually tied race, with Mitt Romney barely ahead of President Obama, 45% to 44%. While the state served as a nearly perfect bellwether of presidential cycles in the 20th-century, it has recently trended Republican. Indeed, by contrast, SurveyUSA reports that in the state's upcoming US Senate race between incumbent Democrat Claire McCaskill and GOP challenger Todd Akin, the Republican leads by a significant +11%, 51% to 40%. Will the addition of Paul Ryan help Romney in the state of Missouri, as well as nationally? Stay tuned.

In yesterday's USA Today/Gallup poll on voter attitudes about Mitt Romney's pick of Paul Ryan, another interesting detail: "The poll also finds 17% of adults say they are more likely to vote for Romney in November because Ryan is his running mate -- about the same impact Sarah Palin had for John McCain four years ago among registered voters." If these numbers hold up, PollTrack believes that Romney's selection could be a significant drag on the ticket. Still, Ryan is relatively unknown to many sectors of the electorate, has his formidable campaign skills have not been tested. PollTrack will be monitoring closely polling on Ryan and his effect on the GOP ticket.

The first poll out of the gate to test the strength of Romney's choice of Paul Ryan as his running mate suggests that the pick may not boost the prospects of the GOP ticket. The poll by USA Today/Gallup reports that "more of the public gives [Ryan] lower marks than high ones. Ryan, a Wisconsin congressman, is seen as only a 'fair' or 'poor' choice by 42% of Americans vs. 39% who think he is an "excellent" or "pretty good" vice presidential choice.  . . . USA TODAY/Gallup Polls of registered voters after the announcements of running mates since Dick Cheney in 2000 all showed more positive reactions. Only Dan Quayle in a 1988 Harris Poll of likely voters was viewed less positively than Ryan, with 52% rating Quayle as a "fair" or "poor" vice presidential choice. The Ryan poll includes all adults, not just registered voters." PollTrack cautions that snap polls often do not take into account the much longer process of voter assessment of candidates. Still, these numbers suggest a problem for the Romney campaign if they persist.

Some commentators have pointed out that the selection of Paul Ryan as Romney's VP candidate may help the GOP team win Wisconsin. While this may be true, the current polling in the state suggests that Ryan may indeed give Romney a modest boost in the state, but not enough to hand the state to the Republicans. Stay tuned to see if future polling suggests a change in this dynamic.

PollTrack has another observation, however: Romney can win election 2012 without Wisconsin (Bush won both the 2000 and 2004 cycles without the state). But is it almost inconceivable according to PollTrack's calculation, that Romney-Ryan can emerge victorious without Ohio (not Republican in modern times has won the presidency without it). With this in mind, would Rob Portman have been a better choice for the Romney campaign  political figure who remains very popular in his home state?

Mitt Romney selection of Wisconsin Rep. Paul Ryan--while an early and dramatic turn in election 2012--may not prove decisive to the outcome. (Few VP picks are.) But PollTrack's biggest caution: do not read too much into polls about the pick. While hardening public opinion can doom or boost a candidate--and the Obama campaign's attempt to define Romney has definitely resulted in a negative downturn in Romney's likeability numbers that may be very difficult to reverse at this point--the true contours of a presidential election often do not become clear until after both party's nominating conventions.

Right now, PollTrack sees the choice of Ryan as a possible net minus for the Romney campaign for one reason: senior voters.

Older voters represent a key and often enthusiastic demographic for the GOP. Yet a recent poll by AARP reports that in the race is tied in the over 50 demographic. This suggests a fundamental problem for Romney. Adding a candidate to the Republican ticket who openly (and unambiguously) calls for a radical restructuring of Medicare and who has referred to Social Security as a "ponzi scheme," and senior voters may have reason to rethink the GOP team. A sharp diminution of support among senior voters (especially voters over 65, who are often the most reliable voters), could spell trouble for Romney-Ryan in the fall. Will Ryan's considerable gifts as a campaigner offset this potential problem? Stay tuned.

A new poll by AARP of voters over 50 reports that President Obama and Mitt Romney are tied at 45% with the group. However, Obama gets just a 42% to 49% approval rating among them. PollTrack notes, however, that in elections past, especially presidential cycles, this voter demographic (especially voters over the age of 60) has tended to trend Republican. A tie in this group--perhaps the result of voter perceptions that Romney may not support Social Security and Medicare as strongly as the president--actually suggests that the GOP challenger is not doing as well as he should among older voters. Stay tuned.

How effective is the Obama campaign's effort to paint GOP challenger Mitt Romney as out of touch with middle-class concerns? According to one poll, at least, the answer may be that these efforts may be suppressing Romney's numbers: the survey by Reuters/Ipsos reports that President Obama has expanded his lead over Mitt Romney, 49% to 42%, this despite the asserting of nearly two-thirds of respondents that "the country is moving in the wrong direction." Reuters observes: "The results of the monthly poll - in which a majority of voters agreed that the economy is the most important problem facing the United States - suggest that the Obama campaign's efforts to paint Romney as being out of touch with the concerns of middle-class Americans could be preventing the Republican from gaining momentum in the race."

According to the latest Quinnipiac/New York Times/CBS News polls in selected key battleground states, President Obama now holds leads (just below or above the 50% mark) in Wisconsin and Virginia, and Mitt Romney is ahead at at 50% in Colorado:

Wisconsin: Obama 51%, Romney 45%

Colorado: Romney 50%, Obama 45%

Virginia: Obama 49%, Romney 45%

According to Gallup, "two-thirds of Americans -- 66% -- have a favorable opinion of former U.S. President Bill Clinton, tying his record-high favorability rating recorded at the time of his inauguration in January 1993. Clinton nearly returned to this level of popularity at two points in his second term, but has generally seen lower ratings, averaging 56% since 1993."

According to Gallup, at this point in Election 2012, only 13-states give the president a net approval rating over 50%. Gallup observes: " A majority of residents in 13 states and the District of Columbia approved of the job Barack Obama did as president during the first six months of 2012. His highest ratings by state were in Hawaii (63%) and Rhode Island (58%), in addition to the 83% approval from District of Columbia residents. In 16 states, his approval rating averaged below 40%, with residents of Utah, Wyoming, and Alaska least approving." Of course, these numbers are to a great extent mitigated by the fact the Obama's GOP challenger, Mitt Romney, scores far lower in approval and far higher in disapproval than the president. Additionally, while Romney likeability numbers remain extremely low (the lowest of any major party candidate in years), the president's numbers remain over 50% (and are even higher in many of the swing states). Here is Gallup's chart:

A new survey by Pew Research reports that President Obama has expanded his lead over Mitt Romney in the presidential race, 51% to 41%. Perhaps, more significantly, the president has passed the 50% mark. The challenge for Romney: as his opponent inches up towards this mark nationally, is voter sentiment actually hardening? As voters start paying attention to the election--and advertising blitzes help to shape perceptions and opinions about the candidates--will sentiment against Romney translate into voters' resolve not to support him in November? While voters have had five years to shape their opinion of the president--he tends to score relatively high in likeability, for example--they are only now beginning to focus their attention on a GOP candidate whose biography has been increasingly defined by his opponent. While the conventions later this month can help shift voter sentiment, post-convention bounces are often short-lived, with candidates soon returning to their pre-convention numbers. Can Romney use his convention to reverse these numbers and bolster support among undecided and unaffiliated voters? Stay tuned.

In another indication that recent news cycles--and heavy advertising by Democrats--has hurt Mitt Romney in key sewing states, a new survey by Quinnipiac University/CBS News/New York Times polls reports that President Obama now leads Mitt Romney in Florida, Ohio and Pennsylvania. Just as significantly, Obama breaks the all-important 50% mark in each state:

Florida: Obama 51%, Romney 45%

Ohio: Obama 50%, Romney 44%

Pennsylvania: Obama 53%, Romney 42%

Despite Mitt Romney attempts to build support among traditionally Democratic Jewish voters--and his trip this week to Israel--a survey by Gallup reports that 68% of Jewish Americans support President Obama for re-eelction, while 25% support Mitt Romney.Thus American Jews remain one of the President's most stalwart group of supporters.