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.
Beto O'Rourke is narrowing the gap between him and Texas Senate opponent Ted Cruz, particularly among independents.
Texas Senate hopeful O'Rourke thinks he's discovered the key to staying humble in Washington.
Two polls out Wednesday indicated a tight race between incumbent Senator Ted Cruz and Democratic challenger Beto O'Rourke.
Senator Ted Cruz told reporters on Monday that he never studied constitutional pardoning, but wrote about the topic in a 2016 Harvard Law journal.
Democrats are eying a first senator from Texas in three decades.
The Trump-supporting sisters claim the social network is censoring their content.
Texas senatorial candidate and El Paso Congressman Beto O'Rourke brought in a staggering $6.7 million during the first quarter of 2018, without taking any PAC or corporate donations. That's more than any other democratic Senate candidate nationwide.
Among Republicans who favored another candidate, there was no consensus on a new contender.
The Trump administration claims the citizenship question will be used to increase data and prevent voter discrimination.
Rights advocates fear the First Amendment Defense Act will be used to discriminate against same-sex couples, single parents and unmarried couples.