O'Rourke isn't taking any money from PACs. He is resolute for demanding term limits for Congress. He refuses to bring in outside mercenaries to help in his campaign. He extols the virtues of working with others across the aisle.
Trump performed terribly in Texas, posting the worst results for a Republican presidential candidate since Bob Dole, in 1996. Trump did particularly poorly with the kinds of suburban, college-educated voters who helped turn Texas into a Republican state in the first place. O'Rourke is very appealing to these voters.
I'm in no way saying he's going to win, as he's got a huge hill to climb. But most of you are underestimating him. He's a very popular born and bred West Texan, unlike Canuck Teddie. If Trump's Presidency takes a nosedive, people like Cruz who have stood idly by will pay for their silence.