(Corrects spelling of Wolf's first name in first paragraph)
By Kevin Murphy
KANSAS CITY, Kan. Oct 8 (Reuters) - Milton Wolf, a Tea Party activist and distant cousin of President Barack Obama, will challenge three-term Kansas U.S. Senator Pat Roberts in the 2014 Republican primary election, Wolf's campaign said on Tuesday.
Wolf, 42, a radiologist, will make the formal announcement on Tuesday evening, according to his website. Campaign manager Ben Hartman confirmed his candidacy.
"If you think that the career politicians in both parties have failed America, join us," Wolf said on his website. "We are building the Wolf Pack - an Army of Davids to defeat the Goliaths..."
Wolf did not respond to a call or email seeking comment.
Wolf said on his website that he is related to Obama through the president's mother, Ann Dunham, who was born in Kansas. Obama's grandmother, Madelyn Dunham, who had a major role in raising the president, is Wolf's mother's cousin, he said.
Roberts, 77, is the latest Senate Republican incumbent to get a challenge from the right in the primary campaign. The others are Michael Enzi of Wyoming, Mitch McConnell of Kentucky, Lamar Alexander of Tennessee and Lindsey Graham of South Carolina. Enzi's challenger is Liz Cheney, daughter of former Vice President Dick Cheney.
Roberts is ranked by several groups as one of the most conservative senators and he is ready to run on that record, Leroy Towns, his executive campaign manager, said on Tuesday.
"It will be pretty hard for anyone to get on the conservative side of Pat Roberts," said Towns.
Roberts' reelection campaign has already raised about $2 million, Towns said. Although Wolf has no experience in politics, Towns said Roberts will take the challenge seriously.
Wolf said he is proud that America elected its first black president in 2008, but that he has "profound differences" with the president.
"Tragically, he misunderstands the greatness of America and believes it is founded in our bloated bureaucracies and government regulations," Wolf said on his website. "He believes America suffers because our government is too small. I believe our greatness is found in our free people and a free market." (Reporting By Kevin Murphy; Editing by Greg McCune and Gunna Dickson)