AUSTIN, Texas — US Sen. Ted Cruz’s newest ad targeting his Democratic challenger is a country jingle that warns, “If you’re going to run in Texas, you can’t be liberal, man.”

Cruz tweeted the 60-second radio ad Tuesday night, shortly after he and US Rep. Beto O’Rourke advanced to a closely watched November matchup.

The ad says O’Rourke “wants to take our guns” and calls him “liberal Robert,” referring to his given first name, and says he “changed his name to Beto.”

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.