Democrats’ hold on the Senate is increasingly at risk

Could Democrats be in danger of losing majority control of the Senate in November? A new analysis from FiveThirtyEight's Nate Silver suggests that the GOP is gaining momentum heading into the midterm elections, putting at least six or seven Democratic Senate seats at serious risk.

"The Democrats now have an approximately 20 percent chance of losing 10 or more seats in the Senate, according to the model, which would cost them control of the chamber unless Gov. Charlie Crist of Florida, who is running for the Senate as an independent, both wins his race and decides to caucus with them," Silver writes in the New York Times.

That analysis directly contradicts what some Republican leaders have said about the November races. All summer, Sen. John Cornyn, head of the National Republican Senatorial Committee, has been downplaying the GOP's chance at taking the majority this fall. Just last week, Cornyn told "Fox News Sunday" that the GOP probably won't make the gains it needs until 2012. "If everything goes our way, I can see a pathway there," Cornyn allowed. "Realistically, I think it'll be a two-cycle effort."

But Democrats in several high-profile races around the country have lost ground against their GOP opponents this summer. They include Barbara Boxer in California and Majority Leader Harry Reid in Nevada.

Still, the party's biggest problem is its standing in several swing-state Senate races. In Pennsylvania, Democrat Joe Sestak, who was once favored in the race, is polling in the double digits behind Republican Pat Toomey. Colorado Sen. Michael Bennet is narrowly losing to Republican Ken Buck. In Missouri, Democrat Robin Carnahan trails Roy Blunt, a Republican U.S. representative seeking to move to the Senate. In Ohio, Democrat Lee Fisher hasn't topped Republican Rob Portman in the polls in months — in spite of Democratic efforts to tie Portman to unpopular policies pushed by his former White House boss, George W. Bush.

These potential setbacks come on top of the list of Democratic seats that seem likely to flip this fall, including Joe Biden's old Senate seat in Delaware, where Republican Rep. Mike Castle is leading. In Arkansas, Sen. Blanche Lincoln, who faced a tough Democratic primary, is losing to her GOP opponent by 32 points — ground she seems unlikely to make up by November.

Still, Silver says the GOP will not only need to sweep Democratic-held seats but also protect their own, including Florida, where Crist and Republican Marco Rubio have been neck-and-neck most of the summer in the race to fill the seat vacated by the retirement of Republican Sen. Mel Martinez.

(Photo of Lincoln by Alex Brandon/AP)