With Harry Reid projected to win reelection to the US Senate in Nevada, PollTrack projects that the Democrats will maintain control of the US Senate.

As many Democratic held seats change hands in the US House, a surprising number of US Senate races remain competitive for Democrats: races in Pennsylvania, Nevada, Colorado, Illinois remain too close to call. Republican candidates were in the lead in all of these races in pre-election polling for these states. This may could be a long evening.

More polling in competitive US Senate Races:

FLORIDA: Quinnipiac Republican Marco Rubio swamps Independent Gov. Charlie Crist, 44% to 30%, with Democratic Rep. Kendrick Meek at 22%.

NEVADA: Suffolk University Democratic US Sen. Harry Reid edges Republican Sharron Angle, 46% to 43%. Rasmussen Angle leads Reid, 49% to 48%.

WASHINGTON: CNN/Time/Opinion Research Democratic Sen. Patty Murray leads Republican Dino Rossi, 51% to 43%.

WEST VIRGINIA: Rasmussen Democratic Gov. Joe Manchin trails Republican John Raese, 49% to 46%,\.

WISCONSIN: CNN/Time/Opinion Research Republican Ron Johnson leads Democratic Sen. Russ Feingold, 52% to 44%.

Here's a recap of the latest polls in some of the most competitive US Senate races:

ALASKA: DailyKos/Public Policy Polling Republican Joe Miller just edges write-in hopeful and incumbent GOP US Senator Lisa Murkowski, 35% to 33%. Democrat Scott McAdams is at 26%.

CONNECTICUT: Fox News Democrat Richard Blumenthal leads Republican Linda McMahon, 49% to 43%.

DELAWARE: Monmouth University Democrat Chris Coons holds a huge lead over Republican Christine O'Donnell, 57% to 38%.

ILLINOIS: Rasmussen Democrat Alexi Giannoulias leads GOP Rep. Mark Kirk, 44% to 43%, with Green Party candidate LeAlan Jones polling at 4%.

NEVADA: Fox News Republican Sharon Angle leads Sen. Harry Reid, 49% to 47%. Public Policy Polling Democrat Reid edges Republican Angle, 49% to 48%.

NEW HAMPSHIRE: Rasmussen Republican Kelly Ayotte is ahead of Democratic US Rep. Paul Hodes, 51% to 44%.

NORTH CAROLINA: High Point University Republican Sen. Richard Burr leads Democrat Elaine Marshall, 45% to 31%.

WASHINGTON: Elway Democratic Sen. Patty Murray leads Republican Dino Rossi, 51% to 38%. Fox News Republican  Rossi just edges Democrat Murray, 47% to 46%.

WISCONSIN Rasmussen Republican Ron Johnson leads Russ Feingold, 52% to 45%. Reuters/Ipsos Johnson leads Feingold, 51% to 44%.

WEST VIRGINIA: Public Policy Polling Democrat Joe Manchin has now reclaimed the lead from Republican John Raese, 48% to 45%.

A Las Vegas Review-Journal/Mason-Dixon poll in the gubernatorial race in Nevada reports that Republican Brian Sandoval holds a considerable +16% lead over Democrat lead Rory Reid, 52% to 36%.

Despite small divergences in the polling of the Nevada U.S. Senate race, it looks like the race is virtually tied at this point. A  Reuters/Ipsos poll reports that the Democratic incumbent Harry Reid holds a narrow lead among likely voters over Republican Sharron Angle, 46% to 44%; a new Rasmussen survey has the race tied at 48%; and a Fox News poll reports a narrow lead for Angle, at 45% to 44%.

A just released Las Vegas Review-Journal/Mason-Dixon poll in Nevada reports that Republican Brian Sandoval holds a considerable lead over Democrat Rory Reid in the race for governor among likely voters, 53% to 31%.

A new Las Vegas Review-Journal/Mason-Dixon poll in Nevada reports that incumbent Democratic U.S. Sen. Harry Reid holds a tiny lead over Republican challenger and Tea Party favorite Sharron Angle among likely voters in the U.S. Senate race, 45% to 44%.

PollTrack Rates The Race Too-Close-To-Call

A just released Las Vegas Review-Journal/Mason-Dixon poll in Nevada reports that Republican Brian Sandoval holds a big, +16% lead over Democrat Rory Reid in the race for governor, 52% to 36%.

One new poll in Nevada suggests that Republican Sharon Angle's downward spiral may have stopped in the race for U.S. Senate. The survey, by Mason-Dixon, shows incumbent Democratic Sen. Harry Reid and challenger Angle are nearly tied. Reid tops Angle among likely voters by a scant 1%, 43% to 42%. Two weeks ago, he held a more significant +7% lead.

Can incumbent Democrat US Senator Harry Reid survive his low approval ratings and win reelection in Nevada? Another poll suggests that he is gaining on his Republican challenger, and Tea Party favorite, Sharon Angle. A new Public Policy Polling survey in Nevada reports that Reid edges challenger Sharron Angle by +2%, 48% to 46%. This is the second poll to report a Democratic lead.

A new Las Vegas Review-Journal/Mason Dixon poll in Nevada reports that incumbent Democratic Sen. Harry Reid has moved into the lead, opening a lead over Republican challenger Sharron Angle, 44% to 37%. It appears that Reid's strategy of painting Angle, a Tea Party favorite as too extreme has paid off.

PollTrack Continues To Rate The Race Too-Close-To-call.

A new Rasmussen survey in Nevada suggests that Senate Majority leader Harry Reid continues to have an uphill battle in his race for reelection. The poll reports that Republican Sharron Angle holds a hefty 11-point lead over Democrat Reid, 50% to 39%.Significantly, Angle hovers at the all-important 50% mark in the poll. 

AR-U.S. Senate Democratic Primary Runoff: Sen. Blanche Lincoln vs Bill Halter. PollTrack Rates The Race Close With A Slight Edge to Halter.

CA-U.S. Senate Republican Primary: Carly Fiorina, Tom Campbell, Chuck Devore. PollTrack Rates the Race Likely Fiorina.

CA-Republican Gubernatorial Primary: PollTrack Rates The Race Likely Meg Whitman.

IA-Republican Gubernatorial Primary: Former Gov. Terry Branstad vs Bob Vander Plaats. PollTrack Rates The Race Close, With A Slight Lead For Branstad.

ME-Democratic and Republican Gubernatorial Primaries: PollTrack Rates BOTH Races Too-Close-To-Call.

NV-Republican Gubernatorial Primary: Incumbent Gov. Jim Gibbons vs. Brian Sandoval. PollTrack Rates The Race Leaning Sandoval.

NV-U.S. Senate Republican Primary: Sharron Angle, Sue Lowden and Danny Tarkanian. PollTrack Rates the Race Likely Lowden

SC-Republican Gubernatorial Primary: PollTrack Rates The Race Likely Nikki Haley.

A new Mason-Dixon poll reports that even when third-party and nonpartisan candidates are included on the ballot, Democrat Sen. Harry Reid loses his reelection race to Republican challenger Sue Lowden. Lowden now leads Reid, 47% to 37%, with the other candidates getting very little support.

A new Mason-Dixon poll in Nevada reports that presumptive Republican nominee, Brian Sandoval, leads Democrat  Rory Reid by a wide margin in the race for governor, 50% to 35%. PollTrack rates the race leaning Republican.

Another poll shows Senate Majority Leader Harry Reid behind in his 2010 reelection race: Rasmussen reports that Reid is considerably lagging behind his potential Republican opponents: he trails Sue Lowden, 54% to 39% and is bested by Sharron Angle, 51% to 40%.

Without the presence of a Tea Party candidate on the ballot in Nevada's 2010 US Senate race, incumbent Democrat and Senate Majority Leader Harry Reid appears to be failing: In hypothetical match-ups, a new Rasmussen survey reports that Republican Sue Lowden defeats Reid by a large margin, 51% to 38%. Similarly, Republican Danny Tarkanian trounces the Democrat, 50% to 37%.

A Mason-Dixon poll in Nevada indicates that incumbent Democratic U.S. Senator Harry Reid actually leads his re-election race with 36% of the vote when matched against a generic Republican who would get 32% and a Tea Party candidate who would get 18%. The ability of the Tea Party candidate to siphon off votes from the Republican candidate is enough to shift the outcome: in head-to-head match ups with named Republicans, Reid continues to trail by  significant margins. Sue Lowden beats Reid, 52% to 39%; Danny Tarkanian would prevail over Reid, 51% to 40%.

Incumbent US Senator and Senate Majority Leader Harry Reid continues to trail his Republican rival in Nevada, now by -8%.

According to PollTrack's first read of the 2010 US Senate Race in Nevada, incumbent Democrat Harry Reid has fallen behind in his race for reelection. PollTrack First Call: Leans Republican

The reelection of US Senate majority leader Harry Reid is far from assured, according to new Las Vegas Review-Journal poll. A whopping 52% of Nevadans are unhappy with Reid, the highest  "unfavorable" rating he's received to date. Just 33% have a favorable view. In hypothetical match ups against three Republicans, Reid loses to each by as much as ten points: Sue Lowden (50% to 40%);  (Danny Tarkanian, 49% to 41%); and even Sharron Angle (45% to 40%).

In another sign that Democrats may suffer loses in the 2010 mid-term election, Sens. Christopher Dodd (D-CT), Blanche Lincoln (D-AR) and Harry Reid (D-NV) all now have disapproval ratings above 50%, according to recent polling. As Tom Jensen observes: "Politics is full of surprises and who knows what unexpected things will happen in the next year but if I had to pick three Senators running for reelection right now who will be cleaning out their offices at this time next year it would be Dodd, Lincoln, and Reid. Once voters have decided the disapprove of you it's very hard to overcome that. "

Is Senator Harry Reid stewardship of health care legislation hurting his 2010 reelection chances in Nevada? According to Rasmussen, the answer may be yes: "Senate Majority Leader Harry Reid continues to lag behind all potential Republican challengers in next year’s U.S. Senate race in Nevada, according to new Rasmussen Reports telephone polling in the state. For now at least, his championing of the president’s health care plan appears to raise further red flags for the Democratic incumbent. Fifty-four percent (54%) of Nevada voters oppose the plan, while 44% favor it. More significantly, however, those numbers include 49% who strongly oppose the plan while only 23% strongly favor it."

Despite his commanding role as Majority Leader, Democratic US Senator Harry Reid is not very popular in Nevada, a problem that is imperiling his 2010 reelection effort: "Nevadans aren't warming up to Sen. Harry Reid, despite plenty of early advertising designed to boost his image, a new poll shows. Just 38% of respondents said they had a favorable opinion of the Democratic Senate majority leader, the same percentage as in October and 1 point higher than in August. The survey of 625 registered Nevada voters by Mason-Dixon Polling & Research suggests the promotional bombardment that Reid launched more than six weeks ago has yet to hit its target. "I'd be worried,' said Michael Franz, an assistant professor at Bowdoin College in Brunswick, Maine, who studies political advertising. 'I'd stop if I had aired ads for two or three weeks and it wasn't moving the needle.' According to the poll commissioned by the Review-Journal, 49% of respondents had an unfavorable opinion of Reid, while 13% were neutral." According to the survey, in hypothetical general election match ups, Sue Lowden (R) leads Reid, 51% to 41%, while Danny Tarkanian (R) leads 48% to 41%.