Of course, there are plenty of examples where corruption or sexual indiscretion ends a political career. No one has forgotten about former Rep. Anthony Weiner, D-N.Y., and his Twitter malfeasance, and the Jack Abramoff scandal wasn't so good to former Reps. Bob Ney and Tom Delay. Even this year there are a number of members from normally safe districts who may lose their seats.
It looks, for example, like Democratic Rep. John Tierney's job of representing the Massachusetts 6th district may come to an end at the hands of Republican Richard Tisei. The number one reason Tierney will be out of a job: his wife kept the books for her brother's illegal gambling operation.
"We have a great candidate in Tisei, but in a district that blue we probably would not have been able to have the same sort of chance that we do," said Dan Conston, a spokesperson for the Congressional Leadership Fund, a super PAC dedicated to electing House Republicans.
But even when a scandal opens the door, it can be difficult to push an incumbent out. This seems to be the case with Rep. Scott DesJarlais, R-Tenn.
It recently came to light that this pro-life freshman conservative demanded that a mistress of his (one he met and courted while acting as her physician) have an abortion. It may feel smarmy, but instead of having to drop out of the race, DesJarlais still has a good shot at reelection.
"The hypocrisy is clear," said Andy Stone, a spokesman for House Majority PAC, which aims to elected Democrats to the House, and which has already made $280,000 worth of ad buys in this race. "It shouldn't play well in his district, a place with strong conservative social values."
It may not play well, but in such a conservative district he may be viewed as the least-bad choice.