Trump's rally for Texas Senator Ted Cruz will be held at NRG Arena, which has only 8,000 seats, while the largest stadium in Texas has close to 103,000 seats.
A new CNN poll found Monday that Texas Senate hopeful Beto O'Rourke was listed as a top 10 candidate for the Democratic presidential nomination in 2020.
Polls last month had offered a major boost to Beto O'Rourke's hopes, but that was before the Kavanaugh Supreme Court nomination fight.
"I am so grateful to him for his service; he's going to go down as one of the greatest presidents. And yet, this [election] is on Texas," said O'Rourke.
"I'm, like, Wow, that's a pretty extreme position, if you're Bill de Blasio," Trump Jr. said, referring to New York City's mayor.
The Texas Senate candidate said he knew the comments were disrespectful.
The senator was recently heckled out of a restaurant in Washington, D.C.
"The biggest gun we've got is called the ballot box. If you don't like who's in there, vote 'em out," sang the country music legend.
Democratic U.S. Senate candidate Beto O'Rourke of Texas, with help from Willie Nelson and other country singers, hosted the largest single-candidate political rally in the country at least since the 2016 presidential election.
Days after protesters in D.C. bum-rushed Sen. Ted Cruz at a D.C. restaurant, the owner announced that he, his staff and their families are being targeted with "life-threatening messages."
Senator Ted Cruz (R-Texas) appears to have been keeping a close eye on his competition.
The Republican and his wife left the Italian restaurant after a crowd entered and began chanting.
O'Rourke complimented Cruz's dedication to his country and thanked him for sacrificing time with his family in order to stand for his beliefs and goals. Cruz took the opportunity to repeatedly compare O'Rourke to Senator Bernie Sanders and to say that he was fighting for socialism.
The race has become one of the most closely watched in the country, with polls putting O'Rourke within a margin of error of Cruz.
"My daughter died. You still have not introduced common-sense reform."
The new poll contrasted with one from a day earlier that showed Ted Cruz with a nine-point lead.
"I have been supporting Democrats all my life," the 85-year-old country icon said.
"I've never seen this kind of mail from a campaign before, or even a legitimate organization. That should tell you something about Ted Cruz," says Gene Wu, Texas state legislator.
"I wasn't likely to vote for Cruz before, but certainly not now," one recipient of the mailer told Newsweek.
The video used 43 of 143 words from an audience member's question, and only 24 of 615 words from O'Rourke's answer.
"Send him back to Ireland!" screamed the Cruz supporter of O'Rourke.
It's not the first time that Texas Republicans have taken a political jab at O'Rourke's character.
"We must send a message that we will fight to make America America again," the lawyer tweeted on Sunday.
David Hogg, a survivor of the school shooting in Parkland, Florida, and the head of an anti-Trump, anti-NRA Super PAC raised more than requested on GoFundMe to put up a Texas billboard featuring Trump ridiculing Sen. Ted Cruz.
"I'm picking the biggest stadium in Texas we can find," Trump tweeted of his rally planned for Ted Cruz.