Pat Roberts

Sen. Pat Roberts (R-Kan.) is cheered by supporters in Overland Park as votes come in Tuesday night. (Chris Neal / Topeka Capital-Journal / August 5, 2014)

One of the last chances for a tea party challenger to oust an establishment Republican came to an end in Kansas on Tuesday night when Sen. Pat Roberts defeated Milton Wolf in the primary.

The three-term senator had 48% of the vote to Wolf's 41% with more than 98% of precincts reporting. Two other candidates split the rest of the votes.

Both campaigns stumbled in a state that has veered to the right in recent years.

Roberts, 78, came under fire this year when it was revealed that he no longer had a home in Kansas, but rented a room at a friend's Dodge City house.

Wolf, 43, used that against him, and Roberts amplified the controversy when he told a radio interviewer last month, “Every time I get an opponent — uh, I mean, every time I get a chance — I'm home.”

Wolf, a second cousin to President Obama, was criticized for posting patient X-rays and insensitive commentary about them on his Facebook page. He apologized and removed the posts, but Roberts questioned his judgment and fitness for office.

Both candidates had attacked the Affordable Care Act, with Wolf calling for it to be replaced by “free-market alternatives for healthcare reform.” Roberts noted that he voted against Obamacare.

Neal Allen, a political science professor at Wichita State University, said Roberts was never in “real trouble because Wolf was such a flawed candidate.”

“The Facebook posts caused him a lot of trouble, and the Roberts campaign really hit him on it throughout the contest,” Allen said. “Roberts has always been staunchly conservative and voted in lock step with his party. The issues with residency were certainly blown up by his challengers, but Roberts has had a presence in the state, and Republicans overall have no ill feelings toward him.”

In November, Roberts will face Democrat Chad Taylor, the district attorney in Shawnee County, which includes Topeka.

Despite tea party groups’ high hopes for the midterm election, most of their efforts to oust establishment Republican lawmakers this year have fizzled — with the possible exception of the standoff in Mississippi, where tea party favorite Chris McDaniel is challenging his loss in a runoff against Sen. Thad Cochran.

And in Michigan on Tuesday night, tea-party-leaning incumbent U.S. Rep. Kerry Bentivolio lost the primary to mainstream Republican challenger Dave Trott.

The most notable upset of the primary calendar drew scant attention from national tea party groups — the toppling of House Majority Leader Eric Cantor by a little-known economics professor in the suburbs of Richmond, Va.

Another chance for the tea party will come Thursday, when two-term Sen. Lamar Alexander of Tennessee will try to fend off state lawmaker Joe Carr.

If Republicans can net six seats in November, they will wrest control of the Senate from Democrats. The GOP is expected to retain its majority in the House.

The splintering of the party at such a crucial time has caused hand-wringing among some Republicans.

But Reince Priebus, chairman of the Republican National Committee, shrugged off the internal debates as helpful exercises to produce the best candidate.

“I'm not one of these people that buy into the theory that primaries are bad,” Priebus said in a recent interview on Capitol Hill. “I think primaries can actually make candidates stronger.”

kurtis.lee@latimes.com

lisa.mascaro@latimes.com

Michael A. Memoli in the Washington bureau and the Associated Press contributed to this report.