Primaries in Michigan, Mississippi and Idaho on March 8, and in Florida, Ohio, Illinois, Missouri and North Carolina on March 15, may prove decisive. If Marco Rubio does not win his home state of Florida, he is cooked, as is Gov. John Kasich if he does not win Ohio.
Ted Cruz already looks to be the last man between Trump and a GOP nomination that has gone, in the last seven elections, to George H. W. Bush, Bob Dole, George W. Bush, John McCain and Mitt Romney.
All five of those nominees since 1988 seem appalled by Trump's triumphs, and only slightly less so by the Cruz alternative.
Not in memory has the leadership of a party been so out of touch. The Republican rank and file are in revolt, not only against the failures of their fathers but the policies of their present rulers.
Some among the GOP elites, who have waited patiently through the Obama era to recapture control of U.S. foreign policy, are now beside themselves with despair over Trump's success.
Fully 116 members of the GOP's national security community, many of them veterans of Bush administrations, have signed an open letter threatening that, if Trump is nominated, they will all desert, and some will defect -- to Hillary Clinton!
"Hillary is the lesser evil, by a large margin," says Eliot Cohen of the Bush II State Department. According to Politico's Michael Crowley, Cohen helped line up neocons to sign the "Dump-Trump" manifesto.
Another signer, Robert Kagan, wailed in The Washington Post, "The only choice will be to vote for Hillary Clinton."
Are they serious?
Victory for Clinton would mean her remaking the Supreme Court, killing all chances that Roe v. Wade could be overturned, or that we could get another justice like Antonin Scalia before 2021.
What are these renegades and turncoats so anguished about?
Trump calls the Iraq War many of them championed an historic blunder. Trump says that, while a supporter of Israel, he would be a "neutral" honest broker between Israel and the Palestinians in peace negotiations, as was Jimmy Carter at Camp David.
Trump says he would "get along very well" with Vladimir Putin, as Richard Nixon got along with Leonid Brezhnev and Mao Zedong.
Trump would launch no new crusades for democracy. He would not oppose Russia bombing ISIS. He would build that wall on the border. He would transfer from U.S. taxpayers to rich allies more of the cost of defending themselves.
Do not most Americans agree with much of this?
Yet this neocon ultimatum about deserting should the voters nominate Trump testifies eloquently to their loyalty.
With every ex-president and ex-nominee repudiating Trump, and foreign policy elites going rogue, the GOP hierarchy is saying: We will cut Trump dead, just as the Rockefeller-Romney crowd cut Barry Goldwater dead.
This is pure my-way-or-the-highway politics.
But it raises anew the question: Can the establishment stop Trump?
Answer: It is possible, and we shall know by midnight, March 15. If Trump loses Florida and Ohio, winner-take-all primaries, he would likely fall short of the 1,237 delegates needed for nomination on the first ballot.
How could the anti-Trump forces defeat him in Ohio, Florida and Illinois? With the same tactics used to shrink Trump's victory margins in Virginia, Louisiana and Kentucky to well below what polls had predicted.
In every primary upcoming, Trump is under a ceaseless barrage of attack ads on radio, TV, cable and social media, paid for by super PACs with hoards of cash funneled in by oligarchs.
But Trump, who is self-funding his campaign, has spent next to nothing on ads answering these attacks, or promoting himself or his issues. He has relied almost exclusively on free media.
Yet no amount of free media can match the shellfire falling on him every hour of every day in every primary state.
Our Principles PAC, backed by Nebraska's billionaire Ricketts family, has poured millions into trashing Trump. American Future Fund is dumping $1.75 million in Florida this week; Club for Growth $1.5 million.
Hedge-fund billionaire Paul Singer is backing the Conservative Solutions PAC, which has dumped millions into anti-Trump ads and plans to spend more than $7 million between March 1 and 15, with $4 million of that going into Florida. The super PAC pile-on is unprecedented.
How well Trump fares in Michigan and Mississippi, measured against how well he was doing in polls last week, will reveal just how successful super PAC savagery has been in changing hearts and minds.
Can millionaires and billionaires who back open borders, mass immigration, globalization and the disappearance of nation states into transnational collectives overwhelm with their millions spent in ads the patriotic movements that arose this year to the wonderment of America and the world?
Has that proud 18th century boast of Americans, "Here, sir, the people rule!" given way to the rule of the oligarchs?