As he showed during Tuesday night’s Republican debate in Las Vegas, Cruz will likely continue to refrain from attacking Trump on his southern swing.

“All you need to do to see why it’s risky to take on Trump is to look at the bodies that litter the campaign trail,” Merritt said. “They are either out of the race or soon will be. He is the most dominant political force we’ve seen. Maybe ever. There is more playbook for how to take him on. It’s much easier and less dangerous to take on a mere mortal candidate.”

Instead, Cruz will continue to portray Rubio as his top political foil. The two senators clashed on immigration during the most recent debate, with each arguing that he is the more conservative candidate.

En route to meet with donors in Beverly Hills, Cruz boasted to reporters just outside of Los Angeles International Airport that Rubio’s campaign was “incredibly nervous that conservatives are getting behind our campaign” in Iowa.