Vice President Joe Biden said today that if Democrats were to lose 35 House seats they currently hold in traditionally Republican districts, it would mean doomsday for President Obama’s agenda.

Biden said Republicans are pinning their political strategy on flipping these seats.

“If they take them back, this the end of the road for what Barack and I are trying to do,” the vice president said at a fundraiser for Rep. Gabrielle Giffords (D-AZ) today in Greenville, Delaware.

Republicans need to pick up 40 seats next November to take back control of the House.

There are 49 seats currently held by Democrats in districts that Sen. John McCain (R-Ariz) won in last year’s presidential election.

Biden said these House seats are Republicans “one shot” at breaking the Obama administration’s agenda. But if Democrats can hold on to those seats, “the dam is going to break,” he said, and a new era of bipartisanship will begin.

“All the hidden Republicans that don’t have the courage to vote the way they want to vote because of pressure from the party … it will break the dam and you will see bipartisanship,” Biden said.

Republicans welcomed the vice president’s assessment of the 2010 landscape.

“What didn’t seem possible just a few months ago, appears to be the topic of conversation even within the upper echelons of the Obama White House,” said Ken Spain, spokesman for the National Republican Congressional Committee. “It is interesting to hear Vice President Biden admit that the administration’s effort to double down on a partisan agenda of government takeovers could possibly mean the ‘end of the road’ for their political viability.”

Knowing that 2010 is going to be a tough year for defending their own turf, Democrats are hoping to stay on offense in several House districts held by Republicans, including Jim Gerlach of Pennsylvania, Mike Castle of Delaware, Mary Bono Mack of California and Joseph Cao of Louisiana.

“From day one, Democrats said this is a challenging cycle but we're aggressively tackling that challenge with outstanding Frontline Members and by putting additional Republican seats in play,” said Jennifer Crider, spokeswoman for the Democratic Congressional Campaign Committee, referring to the most vulnerable Democoratic incumbents. “Republicans have banked on failure by opposing common-sense measures to get the economy back on track and health insurance reform.” 

Biden’s comments came at a fundraiser for Giffords, a Blue Dog Democrat who was first elected in 2006 to represent a district that had been Republican since 2000.

-Karen Travers