AUSTIN, Texas (AP) — Tea party superstars from across the country are converging on Texas in hopes of helping grassroots darling and U.S. Senate hopeful Ted Cruz pull off an upset that had long seemed unthinkable against the mainstream Republican choice Lt. Gov. David Dewhurst.

Former Alaska Gov. Sarah Palin and South Carolina Sen. Jim DeMint are headlining a get-out-the-vote rally Friday night in suburban Houston. That will come a day after fellow tea party favorites, U.S. Sens. Rand Paul of Kentucky and Utah’s Mike Lee, appear at a basketball arena in Dallas on Cruz’s behalf. Paul and Lee will be joined by radio host Glenn Beck and former Texas Rep. Dick Armey, who’s now chairman of the conservative organization FreedomWorks.