“It is part of a bigger narrative,” said Nathan L. Gonzales, a nonpartisan analyst for the Rothenberg Political Report. “I don’t think a general election is going to be won or lost based on that one vote, but I think it will be part of a bigger argument that candidates are going to make against those incumbents who voted for it. It has had more staying power than most votes.”

Support of the bailout is a thread running through the campaigns of Republican Congressional incumbents who have lost in primaries so far this election cycle, and was also a factor in the defeats of three members of Congress in primaries for governor, including that of Senator Kay Bailey Hutchison of Texas.

Across the country, House and Senate challengers are hammering incumbents in both parties who voted for the bailout, in many cases lumping it together with the $787 billion economic stimulus plan passed months later under President Obama, as well as federal aid to automakers.

In Texas, Representative Chet Edwards, a 10-term Democrat, is facing a stiff challenge by Bill Flores, the former chief executive of an oil and gas company, who has assailed Mr. Edwards for his support of the bailout and also the continuing taxpayer subsidies for the mortgage giants Fannie Mae and Freddie Mac.

“Chet Edwards votes for every bailout and against ending any bailout!” Mr. Flores wrote in an e-mail message to supporters, saying Mr. Edwards’s position runs counter to his efforts to convince voters that he is a “really a fiscal conservative.”

Megan Jacobs, a spokeswoman for Mr. Edwards, dismissed the attacks. Referring to the Federal Reserve chairman, she said, “Given Ben Bernanke’s recent statement that TARP helped prevent our country from falling into a second Great Depression, if Mr. Flores wants to put sound-bite politics above the good of our country, that’s a bad choice that will not work in Texas.”

But the bailout issue is not a weapon just for Republicans taking on Democrats. On Thursday Robin Carnahan, the Democratic Senate hopeful in Missouri, criticized her Republican rival, Representative Roy Blunt, a former member of the House leadership, for his vote, calling him “Mr. Bailout.” She took the swipe at Mr. Blunt during her introduction of Mr. Obama at a fund-raiser, not mentioning that Mr. Obama also backed the plan when he was a senator and presidential candidate, as did her brother, Russ, a Democratic House member.