I wonder, though, if he is right about this: “If it weren’t for the black swan event of Trump, Cruz might have effectively locked the nomination up by the end of February.” The post-Reagan Republican party has not chosen people to the right of its center of gravity as its presidential nominees. Presidential nominees have won the primaries with an intraparty coalition of moderates and somewhat conservatives, and “very conservative” voters have been more divided than Republicans to their left.
Trump may–and I’m just thinking out loud here–have helped Cruz get closer to the nomination in two ways. First, by taking so much attention from the media and from voters, he may have kept the very conservative vote from splintering as much as it usually does. The Santorums and Huckabees in the race had no oxygen. Second, Trump himself drew disproportionately from moderate and somewhat conservative voters. He won moderate and liberal Republican primary voters in Wisconsin, for example. Trump’s coalition looks like a shrunken version of the ones that have won in the past. If Cruz ends up winning the nomination, it may be because this time so many moderate and somewhat conservative voters this time chose a candidate who is for various reasons unacceptable to a very large segment of the party.