Jefferson City, Mo. ? Rep. Roy Blunt has been in Congress for 13 years, most of them in the Republican leadership. Democratic Secretary of State Robin Carnahan comes from a family with three generations of Washington politicians.

Yet both Blunt and Carnahan are campaigning against the powers that be as they attempt to win Missouri’s U.S. Senate seat left open by the retirement of longtime GOP Sen. Kit Bond.

It’s a sign of just how unpopular Washington is these days. Senate aspirants across the country are parroting the outsider theme that President Barack Obama himself campaigned on just two years ago. That’s particularly true in the 11 states with open Senate seats.

Just 22 percent of Americans — less than at any previous point in Obama’s presidency — approve of Congress, according to an AP-GfK poll this month. Half say they want to fire their own congressmen. And the frustration is directed at both Republicans and Democrats.

“This is a year when people are very unhappy about the direction of the country. They’re very unhappy in particular about the performance of government and of Congress,” said Dave Robertson, a political scientist at the University of Missouri-St. Louis. “All candidates are going to try to emphasize that they are not part of the problem, but can contribute to the solutions.”

Few candidates face a more interesting challenge in this climate than Missouri’s Senate contenders.

The Carnahans and Blunts are the state’s versions of the Kennedy political dynasty. During the past half-century, members of the two families have served at almost every level of government — from the local school board to the state Legislature to the Governor’s mansion and the U.S. House and Senate.

In the swing state of Missouri, which narrowly went for Republican John McCain over Obama in 2008, Blunt has been running against Obama and the Democratic leadership of House Speaker Nancy Pelosi and Senate Majority Leader Harry Reid.

Carnahan, meanwhile, has been running against a Washington establishment, personified by Blunt, that she decries as mired in partisan gridlock and beholden to special-interest lobbyists and Wall Street executives.