The celebrity physician Dr. Mehmet Oz is preparing to jump into the Pennsylvania Senate race on the Republican side, a move that would shake up contested primary and general election contests.

The 61-year-old Oz has begun hiring a staff and reaching out to potential allies, according to influential Republicans familiar with his plans. It is unclear when he is planning an official announcement.

The Cleveland-born, Delaware-raised, and New Jersey-based Oz rose to national attention as a guest on the Oprah Winfrey Show, where she dubbed him "America's doctor," and later as the host of his own program. A political newcomer who has donated to both Democrats and Republicans, Oz's principal connection to Pennsylvania appears to be his graduate education at the University of Pennsylvania, where he earned both medical and business degrees in the 1980s. He owns a mansion—and is registered to vote—in neighboring New Jersey and bought a vacation home in Palm Beach, Fla., in 2015, according to public records. He does not own property in Pennsylvania, at least under his own name.