Democratic hopefuls Farouk Shami and Bill White will debate in Fort Worth.
Early voting is over and the Texas Democratic and Republican primaries are Tuesday.
Texans who are registered and have lost or misplaced their voter certificates can still cast ballots Tuesday, but must present a valid form of identification and sign an affidavit at the polls.
Republican voters will consider whether to stick with Gov. Rick Perry. U.S. Sen. Kay Bailey Hutchison and party activist Debra Medina are challenging Perry in the GOP primary.
The Democratic front-runner, former Houston Mayor Bill White, faces fellow businessman and political newcomer Farouk Shami in the primary.
The polls are open from 7 a.m. to 7 p.m. Tuesday.
On the Net: http://www.sos.state.tx.us
Copyright Associated Press