Nate Cohn has outlined the election troubles for Mr. Cruz in the next several primaries.

First Cohn lays out why Cruz won in Iowa:

He won Iowa for one reason: He excelled among people who described themselves as “very conservative.” They voted for him by a big margin; he won 44 percent of them to Donald Trump’s 21 percent, according to exit polls. He lost every other ideological category, and often by a lot.

After pointing out that the Republican party primary electorate is more moderate than that in Iowa, Cohn notes:

Even in primary states with well-justified conservative reputations, like Texas or Alabama, “very conservative” voters outnumbered the total of self-described moderates and liberals only by a four-point margin. In the north, “moderate” and “liberal” usually outnumber “very conservative” voters, and often by a wide margin.

That’s why Mr. Cruz has so little traction in New Hampshire. He would be expected to win only about 15 to 17 percent of the vote given the ideological composition of the New Hampshire electorate, supposing he fared about as well among each demographic group as in Iowa. Current polls show Mr. Cruz earning nearly this exact amount.

The conclusion to draw in the generals is that in no way can Cruz bring the roughly forty-two percent who don't declare themselves liberal or conservative to the GOP if he gets the nomination.  In short, nationally, America is right of center, not hard right.  And Cruz has a narrow appeal among them, not to mention the persuadable left-of-centrists.

Enter Rubio, who does better than the other candidates among the forty-two percent and the smaller subset of the swing voters.  He is not, politically speaking, a centrist or moderate, but substantively a conservative.  So what is the difference between Cruz and Rubio?  Tone and personality and image, in my view.  

I trust the moderates and the somewhat conservatives and the very conservatives in the GOP primaries who want to win to spot Rubio's electability and turn away from Cruz (and Trump) and swing toward Rubio, a fine candidate and our future nominee.

James Arlandson's website is Live as Free People, which is updated almost daily and where he has posted How to read the Iowa caucuses, Five reasons not to vote for Cruz, and Twelve reasons to vote for Rubio.