BIRMINGHAM, Ala. — An activist for medical marijuana in Alabama says he’s quitting the Democratic race for U.S. Senate because of a back injury.

Ron Crumpton posted the announcement on his campaign’s Facebook page on Tuesday.

The 49-year-old Shelby County resident wrote that he recently hurt his back, which has given him problems for years. He says recovery will take weeks or months so he’s withdrawing.

Two other people are in the Democratic race. Former federal prosecutor Doug Jones of Birmingham is running, and party officials say Robert Kennedy Jr. of Mobile also has filed paperwork as a candidate.

The primary is scheduled for Aug. 15.