Local scandals in several states with elections vital to Republicans retaining control of the House could reinforce the general "throw the bums out" attitude and help push GOP members out.

"If you look at specific states were corruption has been an issue — places like Ohio where you have Gov. [Bob] Taft embroiled in what was called ‘Coingate,’ where a state official tried to bilk the state government of hundreds of thousands of dollars, if not millions — the width of that scandalis affecting races all over the ballot in the state," said David Wasserman, the house race editor for Larry Sabato’s Crystal Ball, a project sponsored by the University of Virginia’s Center for Politics. "You are seeing [Ohio] Democrats doing much better than would be anticipated without the presence of this shadow casting down over the Republican ticket."

Ohio’s 18th District election is one of the "Dirty Thirty" key races at the core of Democratic hopes to gain control of the House. Thirteen of the 30 races were deemed "toss ups" — that is too close to call — by Sabato at of the end of June. Of those 13, 10 races are in states where there is an ongoing or recent scandal.

Connecticut, for example, with hotly contested races in the 2nd and 4th districts, is still recovering from the corruption conviction of former Republican Gov. John Rowland who finished his 10-month prison sentence this spring. Republican incumbent, Geoff Davis, running for re-election in Kentucky’s 4th District, is likely to be affected by the indictment of Gov. Ernie Fletcher on charges of conspiracy and official misconduct. New Mexico had its state treasurer indicted and Illinois’ former Gov. George Ryan was convicted on federal corruption charges in April.

"A lot of these things at the state level will transfer over to voting behavior at the national level," said Michael Dimock, associate director of The Pew Research Center for the People and the Press. "It does strike me as the sort of thing that would exacerbate a kind of anti-incumbent, we-need-to-change mood that the public may have."

But what of the five open seats — all formerly held by Republicans —where there is no incumbent to contest against?

Even in those races with no incumbent because of retirement — or, in the case of Ohio’s former Congressman Bob Ney, resignation — the sour mood is likely to affect the outcome, Wasserman said.

"The Republicans are the default incumbent party when you figure in the national climate," he said. "And the national climate is half if not more of these contests at this point."