Thompson said the race for the Democratic nomination is getting too crowded.
"If there are four, five, six people, I just get lost in that shuffle," he said.
Thompson said he had hoped to run in a three-way race for the Democratic nomination, possibly against former ambassador Tom Schieffer and humorist Kinky Friedman.
"Right now I’m just re-evaluating because in a three way race, I think I’d have a very good chance," Thompson said. "Schieffer has problems being a Republican and Kinky Friedman has problems being Kinky Friedman."
East Texas rancher Hank Gilbert and Fort Worth teacher Felix Alvarado are also running for the Democratic nomination. Houston Hair-care magnate Farouk Shami and former Travis County District Attorney Ronnie Earle have said they may join the race as well.
Thompson said he's concerned that in next year's primary, he and Gilbert could split the middle class, anti-toll road vote. Friedman, meanwhile, would garner "the cannabis and the freak vote," he said.
Thompson said one of the Democratic candidates asked him to drop his bid for governor but he declined to say who it was.
In 2008, Thompson ran unsuccessfully for Railroad Commissioner. He got 44 percent of the vote against Republican Michael Williams and Libertarian David Floyd.
Thompson's campaign blog is down today and he has not posted to his Twitter feed since August. In July, he reported no contributions but had spent $1,019.26.