Texas Tribune Washington Bureau Chief Abby Livingston said Wednesday that minority turnout for Rep. Beto O'Rourke (D., Texas), the Democratic candidate for U.S. Senate in Texas, could end up being his downfall.

"We are not seeing a lot of evidence that he has excited African-Americans and Hispanics. So that could be his Achilles' heel," Livingston said during an appearance on the "Bill Press Show."

"I went to an event for Hispanics in Forth Worth and two thirds of the people there were white," she said.

When asked about O'Rourke's heritage, Livingston corrected progressive host Bill Press, who was under the impression O'Rourke was Latino.

"He is Robert Francis O'Rourke … Beto is his childhood nickname," Livingston said.

"He's not half-Latino?" Press asked.

"No, he's Irish," Livingston said.

At a campaign event in May, Rep. Vincente Gonzalez (D., Texas) told supporters gathered that O'Rourke was "one of us."

"He’s from the border. … He understands our culture," said Gonzalez, who was born in Corpus Christi, Texas.

At that same event, Gonzalez and O'Rourke were joined by a nine-piece Mariachi band.

O'Rourke is running against incumbent Sen. Ted Cruz (R., Texas) in this year's election. When he was first elected, Cruz became the first Cuban-American to hold the seat. His father immigrated from Cuba.

In 2013, when O'Rourke joined Congress, he was deemed ineligible to join the Congressional Hispanic Caucus.

President Donald Trump is expected to campaign for Cruz in Texas, according to the candidate. While speaking at an NRA event in Dallas, in May, Trump said Cruz has his "full endorsement," which was met with cheers from the crowd.