NASHVILLE (AP) — Tennessee Gov. Bill Haslam says he won't endorse any of the candidates seeking the Republican nomination to succeed him. But he says he has had conversations with several potential hopefuls about the strains that a tough primary fight.

Haslam was the subject of heavy criticism from his rivals for the GOP nomination when he ran for his first term in 2010.

His three opponents attacked him early and often on a range of topics including his refusal to divulge his earnings from the family-owned Pilot truck stop chain; his former membership in a national group called Mayors Against Illegal Guns; and for what they called his likelihood of supporting a state income tax.

Haslam said it takes time to get used to the "personal vulnerability" involved in being a statewide candidate.