Ted Cruz (left) vs. David Dewhurst AP Tea Party candidate Ted Cruz is riding a wave of enthusiasm to a 5-point lead in the Texas Senate runoff election, according to a new poll from Public Policy Polling. The runoff election is set July 31.

PPP found that Cruz has a 5-point lead over Republican establishment candidate David Dewhurst, but that's only half the story. Cruz's lead balloons to an astounding 23 points (59-36 percent) among voters that describe themselves as "very excited" about voting. Dewhurst has big leads among voters that are less enthused, but that doesn't bode well for a July runoff election.

Dewhurst is here because he failed to win 50 percent of the vote in May's Republican primary election. He won only 48 percent of that vote to Cruz's 30 percent. Dewhurst would have avoided a runoff election at 50 percent.

PPP's Tom Jensen wrote that the runoff election polling displays "one of the most stark examples of the Tea Party movement propelling a candidate that we've seen to date."