While positioning himself firmly on the left, O'Rourke has eschewed the anti-Trump rhetoric systematically rolled out by most of his party - a move that has won over voters.
"I think they wanted to see that I'm on his side, and I am, 100 percent", Trump said when asked about why he was heading to Texas.
The president conceded "it got nasty" between the two.
"I honestly couldn't point to anything", she continued, "I'm just trying to - you know, I'm not as educated as I would like to be". "You can add more to it, or you can stay focused on the future and why you did this in the first place".
Several powerful earthquakes strike off the shore of Canada
The Cascadia Subduction Zone has produced magnitude 9.0 or greater earthquakes in the past, and undoubtedly will in the future. The first quake struck off at 6.39am BST, while the second one went off at the same location at 7.16am BST.
Monday's event is something that would've seemed unlikely two years ago.
During the 2016 Republican primary, Trump assailed Cruz as a liar and "dishonest politician", insulted his wife's appearance and promoted unsubstantiated claims that Cruz's father had links to President John F. Kennedy's assassin, Lee Harvey Oswald.
President Trump is scheduled to speak at a "Make America Great Again" rally in Houston, Texas, on Monday night.
Instead, Cruz urged Republicans to "vote your conscience". "Once he was elected president, we had an opportunity, an opportunity to do historic good for the country, for the state of Texas", Cruz said during a campaign stop in his hometown of Houston on Sunday. "His opponent is a disaster for Texas".