WASHINGTON - Being an incumbent is traditionally considered a pretty reliable re-election guarantee for a political candidate. Since 1946, House incumbents have won re-election an average of 92 percent of the time. The re-election rate is lower for the Senate, but still high at 79 percent.
But this year, “incumbent” sounds a lot more like a dirty word.
With the 2010 elections approaching, dissatisfied voters no longer appear willing to give their sitting member of Congress the benefit of the doubt.
Just how toxic is the environment for incumbents? According to The Cook Political Report's House Editor, David Wasserman: In 2008, there were only 24 incumbent House candidates who won less than 70% in their primary elections. Four of them lost. So far in 2010, there have only been seven states to hold primaries, and already 16 incumbents have won less than 70%, including one member who lost his seat earlier this month.
Recent primary losses for two longtime lawmakers — Sen. Bob Bennett of Utah and Rep. Alan Mollohan of West Virginia — have sent a new round of jitters through the ranks of Capitol Hill.
On Tuesday, one of the most consequential primary days of the midterm cycle, voters will decide the fates of candidates in Pennsylvania, Arkansas, and Kentucky. And two more sitting senators — Blanche Lincoln in Arkansas and Arlen Specter in Pennsylvania — have reasons to be nervous.
Specter seems to be in a bit more trouble in his Democratic primary than Lincoln. His opponent, Rep. Joe Sestak, has caught up in the polls — and even surpassed — the 80-year-old incumbent. Specter, who was first elected to the Keystone State seat 30 years ago, had the White House’s endorsement after he switched parties in April 2009. He voted like a hard-line Democrat and led in the polls by more than 20 points for the better part of a year.
But the momentum has shifted to Sestak’s side. Sestak, a former admiral, has gained traction with a hard-hitting ad that ties Specter to former President George W. Bush and Sarah Palin. The ad uses footage of Bush endorsing Specter for the Senate in 2004.
“I can count on this man,” Bush says, adding, “He's a firm ally.”
The ad ends with this brutal line: “Arlen Specter switched parties to save one job — his, not yours.”
Specter says he's doing everything he can to hold on. Vice President Joe Biden, who has campaigned and raised money for Specter before, is scheduled to stump for him one last time on Monday. But Democrats say privately that they don't expect to see either the president or vice president in Pennsylvania next week.
Lincoln still leads primary challenger Lt. Gov. Bill Halter in the polls, but she's got an uphill climb in the fall if she survives. A recent Mason-Dixon poll showed Lincoln leading Halter 44 percent to 32 percent. But, for an incumbent this close to the primary election, being below 45 percent should be worrisome. And, per Arkansas election law, she will need to meet a 50 percent-plus-one-vote threshold on Tuesday to avoid a run-off on June 8th.
The health care debate sparked the moderate senator's troubles. During the lengthy legislative fight over the reform bill, she took flak from both sides; the left attacked her for opposing the public option, and the right didn't like that she worked with Democratic leadership on a bill at all. She eventually voted for the final version of the legislation — after the public option was stripped from it.
During the campaign against Halter, she has stuck by that vote. But the bill remains broadly unpopular with Arkansans — by a 2-to-1 margin in a Mason-Dixon poll in taken in May.
Sensing Lincoln’s vulnerability, Republicans have lined up to oppose her, yielding their own contested primary. GOP Rep. John Boozman leads the crowded field. In hypothetical general Mason-Dixon election matchup, he leads Lincoln by 17 points —and Halter by even more.
The much-discussed ideological rift between Tea Party conservatives and establishment Republicans is once again on display in Kentucky.
Secretary of State Trey Grayson, backed by Washington Republicans like Senate Majority Leader Mitch McConnell, was an early GOP establishment favorite. But it's Rand Paul, son of libertarian-leaning Republican Rep. Ron Paul, who leads by double-digits in most polls. He has been buoyed by the likes of Sarah Palin and conservative Sen. Jim DeMint, R-S.C., who has shown a penchant for bucking party leadership.
A victory for the quirky conservative could be good news for Democrats, who believe they would have a real chance at beating the younger Paul in the statewide general election in November.
Paul's opponent would be either Lt. Gov. Dan Mongiardo — who narrowly lost to sitting (and retiring) Sen. Jim Bunning in 2004 — or state Attorney General Jack Conway. The two Kentucky Democrats have been trading barbs during their tight primary race, with neither enjoying a clear lead in the polls before Tuesday's election.
On Tuesday, there's also a special election in Pennsylvania’s 12th congressional district to fill the seat once held by the late Rep. John Murtha.
The Democratic candidate is Mark Critz, a former Murtha staffer. He faces Republican businessman Tim Burns, who has worked to highlight Critz's ties to the late Appropriations Committee chairman and the ethics issues that swirled around him before his death. Polls show a tossup. Critz is bringing in former President Bill Clinton to campaign for him on Sunday. Sen. Scott Brown, R-Mass., stumped for Burns Friday.
Domenico Montanaro covers politics for NBC News.