Two incumbent Democratic senators are now trailing their Republican challengers in key swing states, a new TIME/CNN/Opinion research poll has found.
In Wisconsin, Sen. Russ Feingold is trailing his GOP challenger by six points, the new survey shows. Republican Ron Johnson leads Feingold in that race 51 percent to 45 percent among likely voters, the poll found, with five and a half weeks to go until Election Day.
Meanwhile, in Colorado, incumbent Democrat Sen. Michael Bennet trails GOP challenger Ken Buck in that state's Senate contest by a five point margin, 44 to 49 percent, the poll of likely voters revealed.
The new survey showed that a Republican is also leading the race for the open seat in Pennsylvania. There, Republican Pat Toomey leads Democrat Joe Sestak, 49 to 44 percent, also among likely voters.
Only in Delaware, where tea party darling Christine O'Donnell recently scored a come-from-behind victory over GOP favorite Mike Castle in the race for the Republican Senator nomination, does a Democrat appear to be on top in the latest TIME/CNN survey of Senate races. There, Democrat Chris Coons leads O'Donnell 55 to 39 percent.
The Delaware results are sure to be a disappointment to Republicans, who until a few weeks ago were thought to have a lock on the Senate seat there. The TIME/CNN survey found that had Castle and not O'Donnell been nominated by the Republicans, voters today would choose Castle over Coons by a 55 to 37 percent margin.
O'Donnell's weakness is particularly noticeable among women, who favored Castle over Coons by a 56-37 margin but who back Coons over O'Donnell nearly two to one. There is one group that O'Donnell has firmly in her back pocket: Tea Party supporters, 85% of whom say they favor her over the Democrat. But Coons leads O'Donnell in every age and economic bracket.
The new poll suggested that deepening fault lines inside the Republican Party were also taking a toll in some other races. In Colorado's gubernatorial contest, Democrat John Hickenlooper is favored by 47% of likely voters to Republican Dan Maes' 21% in the new survey, in large part because conservative third-party candidate Tom Tancredo is attracting an impressive 29% of the vote.
The gubernatorial races in Pennsylvania and Wisconsin, where both incumbents are retiring, also show Republicans with leads. Milwaukee mayor Tom Barrett trails county executive Scott Walker 42-53 in Wisconsin, while attorney general Tom Corbett leads county executive Dan Onorato 52-44 in the Pennsylvania. Of the 37 governorships in play, about half are now regarded as toss-ups.
All four polls were conducted via telephone by Opinion Research Corporation from Sept. 17-21. In Delaware, 703 likely voters were queried; 860 in Colorado; 741 in Pennsylvania; and 963 in Wisconsin. The margins of error for Senate and gubernatorial races are roughly +/-3.5%, while demographic margins range from there up toward +/-8.5%.