WASHINGTON -- Tuesday's high-profile U.S. primary elections may extend a streak of sorts for conservative tea party Republicans: losing individual races but winning the larger ideological war by tugging the Republican Party rightward.

Several tea party-endorsed candidates are struggling in Tuesday's Republican congressional primaries in Georgia, Kentucky and Idaho. In each state, however, the "establishment" Republican candidates have emphasized their conservative credentials.

Democrats say the Republican candidates who are trying to give their party control of the Senate will prove too far right for centrist voters in the November election.

Republicans need to gain six Senate seats to control the chamber. Holding Kentucky and Georgia against well-funded Democrats is crucial to their hopes.

Six states hold primaries Tuesday. Georgia, Kentucky and Oregon have closely watched Republican contests for Senate.

In Kentucky, tea partiers would love to knock off Senate Minority Leader Mitch McConnell, a 30-year senator they see as too accommodating to Democrats.

McConnell, caught off guard by the tea party movement in 2010, has scrambled to win support from conservatives who dislike compromise. He quickly allied himself with Sen. Rand Paul, who defeated McConnell's hand-picked candidate in the 2010 primary.

And in February, McConnell voted against raising the debt ceiling, a vote that past party leaders often swallowed to avert a government default.

Tea party-driven attacks on federal spending have sent Republicans hurrying to tighter-fisted ground.

"We've already changed the narrative, and the Republican Party is running on the principle of limited government," said conservative activist Matt Kibbe, who has feuded with McConnell as political chief of FreedomWorks. "Now we have to figure out what to do with a seat at the table."

Associated Press writers Charles Babington in Washington, Bill Barrow in Georgia and Adam Beam in Kentucky contributed to this report.