BOSTON (Reuters) - Representative Barney Frank, the outspoken, witty Democrat closely tied to the 2008 U.S. bank bailout, faces a tough re-election battle after 15 terms in office at a time when incumbency itself is a liability.
Challenging the Massachusetts liberal is Republican Sean Bielat, a former U.S. marine, and opinion polls suggest Frank has an uncomfortably narrow lead over a political unknown.
In the run-up to Tuesday's congressional elections, Frank has faced a torrent of negative ads and mailings, much of it from groups outside the state who support candidates from the conservative Tea Party movement.
Last week, Frank borrowed $200,000 from his personal savings to prop up his campaign, saying he needed "to defend against outside attacks."
A recent opinion poll showed Frank with 49 percent of likely voters, Bielat at 37 percent and 12 percent undecided. Frank kept his seat in the House of Representatives with 68 percent of the vote in 2008 and ran unopposed in 2006.
Massachusetts has already been the scene of one of the year's biggest upsets, when Republican Scott Brown won a special election for the U.S. Senate seat held for almost five decades by a Democratic Party pillar, the late Edward Kennedy.
"If Barney Frank loses, it would be as significant as Scott Brown's win. You would really begin to see the depths of this anti-government sentiment," said Marc Landy, professor of political science at Boston College.
American voters are in a surly mood over the weak economy, unemployment near 10 percent and the state of the housing market as banks face scrutiny over how they handled the paperwork in home foreclosures across the country.
Frank, 70, has been chairman of the powerful House Financial Services Committee for almost four years.
He helped to broker the $700 billion fund to bail out banks at the height of the financial crisis and he promoted legislation to slow foreclosures and keep afloat Fannie Mae and Freddie Mac, the federally controlled companies that own or guarantee more than half of the $11 trillion in U.S. mortgages.
He was a chief architect of the 2010 Dodd-Frank Act, the Obama administration's plan for tighter regulation of the financial industry.
Bielat's campaign has tagged Frank as a "key player in America's financial collapse" who "has promoted much of what caused the worst economic downturn in decades."
Landy said some see Frank as the "personification of the cozy relationship between the government and irresponsible finance."
Frank's congressional district stretches from the affluent Boston suburbs of Brookline and Newton southward to the working-class towns of Fall River and New Bedford.
The New Bedford Standard-Times newspaper has backed Frank over Bielat, 35, a political novice, former U.S. Marine and project manager at a company that designs and builds robots.
"Recoil from Barney Frank's gruff manner if you will, but his intellect and effectiveness make him invaluable," it said.
Even if Frank is re-elected, some wonder whether he might retire if Republicans gain control of the House, as most polls suggest, and he loses his committee chair.
"Being in the minority is not as much fun," said Alan Wolfe, director of the Boisi Center for Religion and American Public Life at Boston College.
But Frank has unfinished business -- reform of Fannie Mae and Freddie Mac and defense of the Dodd-Frank Act against a Republican assault.
Some veteran lawmakers who lose powerful committee chairs might be tempted to call it a day, especially given the rancor in Washington, but Frank is probably not among them, said Thomas Whalen, a political historian at Boston University.
"He'll never quit," said Whalen. "He'll be taken out of the Capitol on a slab."
Reporting by Ros Krasny; Editing by Ellen Wulfhorst and John O'Callaghan