House Minority Leader John Boehner (R-Ohio) expressed optimism that angry voters to defeat Rep. Mike Castle (R) in the Delaware Senate primary Tuesday night would speak even more loudly against Democrats in November.

The top House Republican, who would likely become speaker under a Republican majority in the House, said GOP members and candidates would have to work closely with voters, including the Tea Party movement, to secure victory this fall.

"The voters of Delaware have spoken, and you're going to continue to hear the American people speak — not just last night, but you're going to hear them speak come November," Boehner said at a press conference on Capitol Hill.

Conservative insurgent candidate Christine O'Donnell upset Castle, a more centrist Republican, in a Senate primary last night that effectively ended Castle's long career in Congress.

Boehner said he'd admonished his members to be mindful of the voter anger bubbling up throughout the electorate, especially in the Tea Party movement.

"You've heard me talk all year about the rebellion that's going on in America," he said. "I talked to my members a year and a half ago about the fact that they need to work with their constituents, they need to listen to their constituents, they need to engage with people."

Republican Party leaders have suffered from a somewhat unwieldy relationship with the Tea Party movement, which could prove to be a decisive voting bloc in this fall's elections.

The movement has provided the GOP with energy, money and momentum against incumbent Democrats — major boosters to Republicans as they look to take back the House, and possibly the Senate.

But the movement has also turned its anger at times against Republicans, meaning the defeat of some incumbent House GOP members in primaries and losing campaigns for a number of candidates favored by establishment Republicans at the hands of insurgent conservatives such as O'Donnell.

Boehner said all Republican members and candidates would have to make an effort to work with highly engaged constituents to make sure they turn out this fall.