"If you're gonna run in Texas, you can't be a liberal man," sang the man's voice on Ted Cruz' latest political advertisement. "Cause liberal thought is not the spirit of the Lonestar man."

It's a radio ad from Cruz' re-election campaign and the Republican Senator first previewed it on his twitter page Tuesday night.

Cruz tweeted the 60-second ad shortly after he and Democratic Rep. Beto O'Rourke made it through the primaries and on to a closely watched November election showdown.

The ad later said O'Rourke "wants to take our guns" and called him "liberal Robert," referring to his given first name. It also said he "changed his name to Beto."

(Don't forget: Cruz also uses a nickname for his given name, Rafael Edward Cruz.)

O'Rourke is raising more money than Cruz so far, but remains very unlikely to win in November. Texas has not elected a Democrat statewide since 1994.