Mr. Cruz and Florida Sen. Marco Rubio were the big losers. Mr. Cruz fell behind Ohio Gov. John Kasich as the GOP runner-up to Mr. Trump, along with Mr. Rubio, the third-place finisher in Iowa, who self-destructed with a robotic performance in that primary-eve New Hampshire debate.
Ironically, the chief architect of Mr. Rubio's deflation was New Jersey Gov. Chris Christie, who first cited the Florida senator's vulnerability, did not benefit much for his role as executioner. He finished sixth in the squabble and announced Wednesday that he was suspending his campaign.
The fact that the competition among some GOP also-rans will go on in the wake of the New Hampshire voting is yet another political blessing for Mr. Trump. His ability to garner one-third or more of the Republican vote remains enough to keep him in the catbird seat.
The wishful thinking of the also-rans like Messrs. Kasich and Rubio and former Florida Gov. Jeb Bush is that one of them eventually will survive to go one-on-one against Mr. Trump, when his one-third of the vote will not be enough to take the nomination.
On the Democratic side, no similar crowded field exists that could work the same magic for Hillary Clinton as she moves on to the next tests against Mr. Sanders in their party -- caucuses in Nevada on Feb. 20 and the South Carolina primary on Feb. 27.
Instead, she must establish the upper hand over a lone opponent in both states, but with certain perceived advantages that were not present in New Hampshire. Nevada's substantial Latino population and South Carolina's large African-American vote could hold the key to a Clinton comeback.
Thereafter, on March 1, in what has been dubbed the "SEC primary" (as in the Southeastern Conference in college sports) and "Super Tuesday," citizens of Alabama, Arkansas, Georgia, Oklahoma, Texas, Tennessee, Vermont and Massachusetts will vote in primaries, and Minnesota and Colorado will hold caucuses.
Ms. Clinton enjoys broad support among the party establishment, especially women hoping to make the former first lady the first female president, and her campaign is in a strong financial position. Her super PAC called Priorities USA Action, which reported $45 million in cash at the close of January.
The strategy anticipates the building of a political firewall to blunt the Sanders surge as the campaign calendar moves through the South, where the self-declared democratic socialist may encounter considerable conservative opposition.
At the same time, Mr. Sanders can be expected to continue his populist assault on Ms. Clinton's reliance on big donors from the financial sector. In his long and rambling primary victory speech on national television, he converted much of it into a fund-raising pitch to small donors who have been the heart of his own campaign treasury. In January, he reported raising $20 million, more than $5 million more than his opponent.
Driving home his message that his opponent is heavily financed by Wall Street interests, Mr. Sanders boasted, to much cheering, that he does not have a super PAC and does not want a super PAC.
Ms. Clinton in the final days in New Hampshire bitterly accused Mr. Sanders of employing a "very artful smear" in implying she had voted for such interests to get their money. She said his comments "by insinuation and innuendo" are not "worthy of you." Sanders denied the allegation, saying he had pledged not to resort to a negative campaign against her and had kept his word.
Her husband, former President Bill Clinton, entered the fray, repeating the charge on the stump, but nothing he said could avert the one-sided loss she suffered in the state she had won against Barack Obama in 2008.
So it's on to Nevada and South Carolina, where both party establishments continue their fights to ward off the very different outsider challenges of Messrs. Trump and Sanders.
Jules Witcover is a syndicated columnist and former long-time writer for The Baltimore Sun. His latest book is "The American Vice Presidency: From Irrelevance to Power" (Smithsonian Books). His email is firstname.lastname@example.org.