“Late Show” host Stephen Colbert said Sen. Ted CruzRafael (Ted) Edward CruzTrump changes mean only wealthy immigrants may apply, says critic The Hill's Morning Report — Ford, Kavanaugh to testify Thursday as another accuser comes forward Viral video shows O’Rourke air-drumming to the Who’s ‘Baba O’Riley’ after Cruz debate MORE (R-Texas) is “scared” of Rep. Beto O'RourkeRobert (Beto) Francis O'RourkeFive takeaways from Cruz, O'Rourke's fiery first debate O'Rourke rakes in .1M online in August Texas showdown: Cruz, O'Rourke to face off in debate MORE (D-Texas) as the Democratic challenger continues to gain momentum in a state that generally favors the GOP.

“Beto is running in Texas against incumbent senator and man whose campaign staff is definitely watching this show right now, Ted Cruz,” Colbert during his show on Wednesday night.

“You know it’s bad when you need backup from a man with a 36 percent approval rating. Their backup plan is a celebrity endorsement from the herpes virus,” Colbert joked, referring to President TrumpDonald John TrumpHouse Republican threatens to push for Rosenstein impeachment unless he testifies Judge suggests Trump’s tweet about Stormy Daniels was ‘hyperbole’ not defamation Rosenstein faces Trump showdown MORE's plan to hold a "major rally" for Cruz in October.

“Here’s how scared Ted Cruz is of Beto O’Rourke,” Colbert went on to explain during the late-night program. “He bought ads on my show tonight to counter his interview.” 

Colbert then took aim at some of the attacks the Texas Republican Party launched against the congressman for declining to debate Cruz, including an old photo of O’Rourke’s days in a rock band along with the caption: “Maybe Beto can’t debate Ted Cruz because he already had plans.”

“Yes, his plans were being smoking hot in a naughty but approachable sort of way, like your best friend’s older brother who smells like weed and listens to Radiohead,” Colbert said. “Read us your poems, Beto!” 

After taking several jabs at the Texas Republican Party’s efforts to thwart O’Rourke’s campaign, the comedian then brought out the congressman for an interview.

During the interview, O’Rourke attacked Trump’s proposed border wall when asked about the idea of one being built in Texas.

"We don't need walls," O'Rourke said. "We can have smart security solutions." 

The Texas Democrat, who is from El Paso, also said his hometown is one of the safest in the United States because it is a city of the immigrants.

“We greet one another with respect and dignity,” he told Colbert.

“People are coming out at this moment of truth,” O'Rourke continued. “They’re going to help us decide as a country, are we a nation of walls? Will we ban all Muslims or all people of one religion? Will we describe the press as the ‘enemy of the people’? Will we take kids away from their parents when they’re trying to claim asylum, fleeing from the most brutal countries in this hemisphere, if not the planet?”

According to a new poll by CBS Dallas-Fort Worth/Dixie Strategies, Cruz and O'Rourke are neck and neck in the Texas Senate Race, with the Republican leading his challenger by only four points, within the margin of error.