Veteran US Sen. Roberts wins Kansas GOP primary

By JOHN HANNA | August 5, 2014 | 11:34 PM EDT

FILE - This, July 14, 2014, file photo shows Sen. Pat Roberts, R-Kan., in Olathe, Kan., as he speaks at rally for Kansas Gov. Sam Brownback. Senate and House incumbents in Kansas, Michigan and Missouri are trying to beat back challengers on Aug. 5 in the kickoff to a busy month of primaries. Voters in Washington state consider the qualifications of a dozen candidates vying to replace a two-decade congressional Republican who is retiring. In Kansas, Roberts faces Milton Wolf, a radiologist and the second cousin of President Barack Obama. (AP Photo/Charlie Riedel, File)

TOPEKA, Kan. (AP) — U.S. Sen. Pat Roberts fended off an aggressive challenge Tuesday to win the Republican nomination for a fourth term, despite attacks from his tea party foe that the incumbent had lost touch with Kansas voters.

Milton Wolf, 43, a Leawood radiologist making his first run for public office, failed to pull the upset in the race against Roberts, 78, whose political career dates to the late 1960s, when he was a congressional aide.

After surviving the primary, Roberts is a huge favorite to win his fourth, six-year term in November. Republicans enjoy a nearly 20 percentage-point advantage among registered voters and have won every U.S. Senate race in the past 80 years.

Wolf has said he is a distant relative of President Barack Obama but stresses his strong opposition to the Democrat's signature health care overhaul. He said his mother and Obama's grandmother were cousins, describing himself as a second cousin, once removed, of the president. He acknowledges that they did not meet until after Obama was elected.

Roberts overcame an early-July gaffe in a radio interview about the rented space in a Dodge City home he lists as his official residence and attacked Wolf relentlessly over questionable postings of graphic X-ray images on a personal Facebook page in 2010.

Wolf had the backing of national tea party groups that were energized by U.S. House Majority Leader Eric Cantor's loss in Virginia's GOP primary in June.