Paul Ryan, Wasserman Schultz to test anti-establishment mood

Here's a look at noteworthy contests, a prelude to a November election in which Democrats will make a long-shot bid to capture House control:

The U.S. Chamber of Commerce and the Ending Spending Action Fund, which wants to curb federal expenditures, spent big dollars against him.

An unlikely defeat in the Aug. 9 primary would probably spell political doom for the GOP's 2012 vice presidential candidate and potential future presidential contender.

Nehlen got a boost from Trump when the GOP presidential candidate said in a Tuesday interview with The Washington Post that he is "not quite there yet" in endorsing Ryan.

Ryan campaign spokesman Zack Roday expressed confidence in a primary victory and said, "Neither Speaker Ryan nor anyone on his team has ever asked for Donald Trump's endorsement."

Not taking chances, Ryan is airing his third TV ad, with people waving flags and praying as Ryan tells the camera, "I am committed to securing our borders."

Vermont Sen. Bernie Sanders complained that Wasserman Schultz's DNC, which historically has remained neutral in presidential primary season, backed his victorious Democratic presidential rival, Hillary Clinton.

—Republican Rep. Jeff Miller is leaving a Panhandle seat so conservative that one leading competitor, State Sen. Greg Evers, raffled off an AR-15 rifle among people who "liked" his Facebook page.

—A Sept. 13 challenge to Rep. Frank Guinta, R-N.H., perhaps the most endangered House incumbent, whom the Federal Election Commission said accepted illegal 2010 campaign contributions from his parents.