One year before their likely matchup in a key 2010 Senate race, Democrat Robin Carnahan and Republican Roy Blunt are locked in a dead heat, according to a Public Policy Polling survey conducted Nov. 13-15.

Carnahan, the Missouri Secretary of State, drew 43 percent support in the poll of 763 voters. Blunt, who represents the southwestern 7th District in the U.S. House, had 42 percent.

Carnahan is running even with Blunt even though more respondents think unfavorably (38 percent) than favorably (30 percent) of the Republican. Carnahan is viewed favorably by 40 percent and unfavorably by 36 percent.

Republican Michael N. Castle has taken a 15-point slide and now trails Delaware Attorney General Beau Biden in a hypothetical matchup for the 2010 election to fill the Senate seat vacated by Biden's father, Joseph R. Biden Jr., according to a poll conducted Nov. 10-15 by Susquehanna Polling and Research, Inc.,

The poll shows Biden now leading Castle 45 percent to 40 percent, with 8 percent undecided and 6 percent saying they would vote for someone else.

In a Susquehanna poll in April, Castle was leading Biden 55 percent to 34 percent.

Less than six months before the primary election, Ohio voters don't know much about the Democratic and Republican candidates who are running for a key open Senate seat, according to a Quinnipiac poll taken Nov. 5-9.

More than half of respondents said they didn't have enough information to render either a favorable or an unfavorable impression of Republicans Rob Portman and Tom Ganley and Democrats Lee Fisher and Jennifer Brunner, who are vying to succeed retiring GOP Sen. George V. Voinovich.

But the poll did show a shift toward the Republicans in that President Obama's disapproval rating in Ohio (50 percent) is now higher than his approval rating (45 percent). And Portman, a former House member from the Cincinnati area and the party-endorsed candidate for the Senate, now has slight leads over Fisher, the lieutenant governor, and Brunner, the Ohio secretary of state.

Connecticut Sen. Christopher J. Dodd is running behind or even with each of five of his possible Republican opponents, including political newcomers who have not held elective office, according to a Quinnipiac poll taken Nov. 3-8.

Dodd is in serious trouble with his constituents, 49 percent of whom rate him unfavorably, while 42 percent rate him favorably. His job approval rating also is under water, with 40 percent approving and 54 percent disapproving of the job he has done as a senator.

Dodd's job approval has lagged behind his disapproval for more than a year, and polls since last spring have shown more people rating him unfavorably than favorably.

A plurality of Republican voters in California are up in the air about the 2010 Senate, but those who have an opinion are split evenly between GOP candidates Carly Fiorina and Chuck DeVore, according to a USC/Los Angeles Times Poll conducted Oct. 27 through Nov. 3 by Greenberg Quinlan Rosner Research.

Forty percent of registered Republicans said they were undecided about whom they want to take on Democratic Sen. Barbara Boxer next November. Twenty-seven percent each said they would back former Hewlett-Packard CEO Fiorina, who officially entered the race last week, and Devore, a state assemblyman from Irvine, Calif. who has been campaigning for several months.

Fiorina has a far higher profile in political circles and the media than DeVore given her past leadership of tech titan H-P and a stint as advisor for 2008 Republican presidential nominee John McCain, but that doesn't appear to have trickled down to the average California voter. The pair had some of the lowest name recognition rates among a long list of California politicians and candidates -- 29 percent could identify Fiorina and just 19 percent could identify DeVore.

Florida Gov. Charlie Crist's main opponent in his coming race for Senate may be his own sagging popularity among the state's Republican voters, according to a poll conducted Oct. 25-28 and commissioned by three Florida news organizations.

Crist angered some of his fellow Republicans last February when he appeared on stage for an event with President Obama to build support for an economic stimulus package that was widely opposed by the GOP.

About two-thirds of Republican voters responding to the poll disagreed with Crist's decision to appear with the president, and half of them said they strongly opposed it, according to The Miami Herald, one of the news organizations sponsoring the survey. The other two news sponsors were Bay News 9 and the St. Petersburg Times.

Pennsylvania Sen. Arlen Specter's lead over his Democratic primary rival, Rep. Joe Sestak, has dwindled since summer, according to a Franklin and Marshall College poll conducted Oct. 20 to 25.

The survey found Specter ahead of Sestak by 12 points, 30 percent to 18 percent, but 47 percent said they were undecided.

In a similar poll from the end of August, Specter led Sestak by a larger margin, 37 percent to 11 percent, among polled registered Democrats.

Matched against likely Republican nominee Pat Toomey, a former congerssman, the latest poll of 529 registered voters put Specter in the lead by the narrowest of margins -- 33 percent to 31 percent, with 30 percent undecided. The margin of error was 4.3 points.

Specter switched parties after polls showed he would have a hard time winning a Republican primary against Toomey. But the Franklin and Marshall survey is the latest in a series of independent polls showing that voters aren't certain that Specter deserves a sixth Senate term.

CQ Politics currently rates the general election race Leans Democratic.

-- Shira Toeplitz

Attorney General Martha Coakley continues to look strong against both her fellow Democratic candidates and against the likely Republican nominee in the Massachusetts Senate special election, according to a Western New England College Polling Institute survey conducted Oct. 18-22.

With just over a month to go before the Dec. 8 primary, Coakley leads the Democratic field with 37 percent among registered voters. In a bit of a surprise, the survey found investor and Boston Celtics co-owner Stephen Pagliuca running neck-and-neck with six-term U.S. Rep. Michael E. Capuano for second place. Pagliuca is at 14 percent and Capuano at 13 percent.

Alan Khazei, the co-founder of community service program City Year, trails at 4 percent of the vote. Twenty-six percent of voters were still undecided.

Former Florida state House Speaker Marco Rubio is cutting into Gov. Charlie Crist's lead in the Republican Senate primary, according to a Quinnipiac University Polling Institute survey conducted Oct. 12-18.

Crist led Rubio by 29 points in mid-August, but in the latest survey, the popular governor was ahead of Rubio 50 percent to 35 percent.

"Gov. Charlie Crist's lead ... has come back down to earth. His margin is still formidable, but obviously Marco Rubio's focus on convincing Republican conservatives that he, not Crist, is their kind of guy is bearing fruit," said Quinnipiac University Polling Institute Assistant Director Peter Brown.

Forty-four percent of Republican voters surveyed said they have a favorable opinion of Rubio while just 3 percent have an unfavorable opinion and 52 percent said they haven't heard enough about him.

The likely Democratic and Republican nominees for the Senate in Delaware next year are very well-regarded by voters and are locked in what would be a tight race, according to a Research 2000/Daily Kos poll conducted Oct. 12-14.

The survey gave Republican Rep. Michael N. Castle, who announced his candidacy last week, 46 percent of the vote in a hypothetical November 2010 matchup against Democratic state Attorney General Beau Biden, who had 45 percent.

Biden, who is interested in seeking the seat long represented by his father, Vice President Joseph R. Biden Jr., has an approval rating of 65 percent and a disapproval rating of 29 percent. Castle, a former Delaware governor, has nearly identical ratings, with a 64 percent approval rating and a 30 percent disapproval rating.