In New Hampshire, Trump is strong; the Iowa winner will get a bump; and even as the archconservative candidates fought against “winnowing” in Iowa, the remaining center-right candidates will go for broke, including Chris Christie, newly invigorated by his own strong debate performances, plus an endorsement from the Union-Leader.

Rubio’s running neck and neck with Ted Cruz in South Carolina polls, but the Texan probably has the higher upside in this profoundly conservative state. And Cruz has planned his entire campaign around winning the so-called “SEC Primary” on March 1. And on March 15, he will face the existential challenge of a winner-take-all Florida primary he cannot afford to lose. So far, in sporadic polling, Rubio has topped out at 18 percent in his home state.

His hopes for an early splash may depend on the unlikely venue of Nevada, where his early years as a an ex-Catholic Mormon in Las Vegas reportedly could give him an edge among the LDS voters whose mobilization for Mitt Romney played an outsize role in that state in the last two cycles.