No to Trump as preordained nominee - this fight is not over by any means.
https://www.washingtonpost.com/news/volokh-conspiracy/wp/2016/03/02/so-far-trump-wins-open-primaries-and-cruz-wins-closed-and-the-calendar-is-starting-to-change-toward-more-closed-primaries/Following the South Carolina primary, an interesting article by Michael Harrington went around Facebook that speculated that Donald Trumps victory in the South Carolina primary was attributable to Democrats voting in the Republican (open) primary. One of the good things about Harringtons article is that he put out a testable hypothesis that turnout in the Democratic primary a few days later would be less than 390,000. In fact, it was 367,000. Harrington concludes that had South Carolina had a closed primary, Ted Cruz would have won the primary there. I dont know him and the author seems to be anti-Trump based on other things he has written but the fact that his prediction was borne out adds some independent verification to his thesis. So that got me to thinking.
If true, why does this matter? Because so far the primary calendar has been heavily tilted toward open primaries. But there have been four closed elections: the Iowa caucus, the Nevada caucus, and Super Tuesdays Oklahoma primary and Alaska caucus. Ted Cruz won three of those four closed elections.
So heres where it potentially gets interesting. Although the media are looking forward to March 15, this Saturday (March 5) there are four Republican primaries/caucuses: Kansas, Kentucky, Louisiana and Maine. All are closed.
Then, once the winner-takes-all states begin, a large number of those are closed primaries and caucuses as well (including Florida, for what its worth).
That suggests at least two things.
First, the fact that South Carolina and most of the SEC primaries were open primaries may very well explain why those states did not turn out to be Ted Cruzs firewall or launch states as he had predicted. Oklahoma did perform as expected, being a fairly comfortable win for Cruz. The timeless Pauline Kael quote that has been back in circulation lately may not necessarily be incorrect among actual Republicans.
Second, the four closed primaries and caucuses this Saturday could be very interesting to watch, particularly to see whether Trump can maintain his momentum in closed primary states where he will have to appeal to the traditional Republican base. I havent gone through the remainder of the states to calculate in detail how many delegates will be selected through this series of closed primaries and whether those are enough to win. Trump also might start winning closed primaries and caucuses. But this has been his Achilles heel so far.