FILE - In this May 10, 2018 file photo, Kendra Horn speaks during a forum for Oklahoma 5th congressional district seat Democratic candidates in Edmond, Okla., on May 10, 2018. Horn is the latest candidate to announce plans to run for Oklahoma's soon-to-be vacant U.S. Senate seat. The 45-year-old attorney told The Associated Press on Tuesday, March 15, 2022, that she plans to seek the seat being vacated by Republican Sen. Jim Inhofe. (AP Photo/Sue Ogrocki, File)

OKLAHOMA CITY (AP) — Democrat Kendra Horn is the latest candidate to announce plans to run for Oklahoma’s soon-to-be vacant U.S. Senate seat. The 45-year-old attorney told The Associated Press on Tuesday that she plans to seek the seat being vacated by Republican Sen. Jim Inhofe. Horn pulled off one of the biggest upsets in the 2018 midterm elections when she defeated then-U.S. Rep. Steve Russell, a Republican. She served one term before losing the seat in 2020 to U.S. Rep. Stephanie Bice. Several high-profile Republicans have already announced plans to run, including U.S. Rep. Markwayne Mullin, former Oklahoma House Speaker T.W. Shannon, state Sen. Nathan Dahm and Inhofe’s longtime Chief of Staff Luke Holland.