In a nutshell, Cruz has lost to Trump because he ran as a professional politician, using the semi-permanent professional campaign apparat to slice and dice the voters into various interest groups while limiting access to the mainstream media. Trump has run a broad campaign appealing to a large number of GOP voters on a few critical issues: immigration, economic security and an America First foreign policy.
I believe Trump will win the general election on those issues, and will expose all of the Clintons' and Obama's malfeasance to boot, blasting through the media barrier. He did that today about Benghazi, tying Clinton's and Obama's failures there directly to ISIS' gains.
Not only will he beat her but he's the only Republican who could beat her. The only one impervious to the Clinton/DNC/MSM slime machine. I love the way that Democrats say the GOP should nominate someone "sensible" like Kasich. They'd destroy him if that happened.