Having trailed Ted Cruz by as much as 10 points in recent Iowa polling, Donald Trump decided to play No More Mr. Nice Guy with the Texas senator in the sixth GOP televised debate in South Carolina on the Fox Business Network.
Their early lovefest ended when the brash Texan assaulted Mr. Trump's "New York values," attempting to tap into the regional dislike of the Big Apple. "I can frame it another way," Mr. Cruz said. "Not a lot of conservatives come out of Manhattan. I'm just saying."
The Manhattan billionaire thereupon deftly reminded the audience of the city's rousing reply to the 9/11 terrorist attacks on the World Trade Center as an inspirational, patriotic episode in the nation's history.
"I saw something that no place on Earth could have handled more beautifully, more humanely than New York," he declared, in full indignation. "That was a very insulting statement that Ted made."
In one stroke, Mr. Trump put Mr. Cruz in his place. It was another demonstration of the New Yorker's sensitivity to the American pulse that continues to make him such a formidable political force in the current climate of public anger and resentment.
At the same time, Mr. Trump doubled down on his latest suggestion that Mr. Cruz's eligibility for the presidency is in doubt because he was born in Canada of an American-born mother. Declaring that the senator may not be a "natural born citizen" as stipulated in Article II of the Constitution, Mr. Trump challenged Mr. Cruz to seek a clarifying declaration from a federal judge.
Mr. Trump, by attempting to muddy the picture, can argue that the Democrats could well bring a legal suit against Mr. Cruz, leaving what he called "a big question mark on your head" during the campaign.
It was another example of Mr. Trump's crafty ability to keep Mr. Cruz off balance as he defends his own claim to be the representative of fed-up America in leading the Republican Party against the Clinton-Obama era of liberal dominance.
The latest debate also illustrated the challenge to the other GOP presidential candidates to gain a foothold in the nomination contest. They are cast as would-be defenders of the old Republican establishment of high state and federal officeholders against the outsider upstarts.
Debate subplots continued in which former Florida Gov. Jeb Bush, Florida Sen. Marco Rubio, New Jersey Gov. Chris Christie and Ohio Gov. John Kasich scrambled to grab television air time. They have effectively been reduced so far to being orthodox party pleaders bucking the anti-establishment fever that has seized the party of Eisenhower, Reagan and the Bushes.
Jeb Bush particularly sought to cast the candidacy of either Messrs. Trump or Cruz as a ticket to the election of the Democratic frontrunner in the fall. "Everybody on this stage is better than Hillary Clinton," he said. "I think the focus ought to be on making sure that we leave this nomination process, as wild and wooly at it's going to be, to unite against Hillary Clinton because she is a disaster." Mr. Trump responded again by saying of Mr. Bush that "we don't need a weak person being president of the United States."
The debate also suggested the further decline of the other early outsider favorite, retired neurosurgeon Ben Carson, who offered more platitudes. Republicans had to stop their bickering, he said, because "if we manage to damage ourselves and we lose the next election and a progressive gets in there and they get two or three Supreme Court picks, this nation is over as we know it."
The Republican television debate was the last one before the Iowa precinct caucuses on Feb. 1. The latest polls have Mr. Cruz ahead but indicate Mr. Trump is closing the gap; caucus night turnout is deemed critical to the outcome. But at last the gloves are off between them as actual voting is about to begin, and all the sound and fury will finally be measurable in this most uncommonly bitter and contentious GOP leadership struggle.
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 email@example.com.