When House Speaker Paul Ryan released a video laying out his familiar theme that politics should be fought on ideas and issues, the Drudge Report’s headline was: “Paul Ryan launches his first campaign ad.”

A dream of some Republicans is that Ryan will rescue them from a looming fiasco in the presidential election. That’s not likely. As states assemble delegates for the party convention, there are already demands that no votes be cast for someone who didn’t run.

It would be rational to turn to Gov. John Kasich or Ryan, who might win the election, but neither the season nor the Republican grassroots reward rationality.

If Donald Trump goes into the Republican convention with close to the 1,237 delegates required to win the nomination, it would be hard to deny him. It’s more likely that he’ll come in about 100 votes shy.

That’s why in the days leading up to the Cleveland gathering, all eyes will be on the rules and credentials committees, most of whose members haven’t yet been chosen by state delegations. These panels can come up with procedures to thwart Trump.

The temptation to do so will be great, despite the havoc he could wreak. It’s a myth that the Republican anti-Trump movement is just the establishment. It includes prominent officeholders and donors, but also movement conservatives and leading economic and national security advisers. They are convinced that Trump would be an electoral disaster — polls show that he’s the most unpopular political figure in modern times — and that he would splinter the party.

Already some Republican politicians say they won’t back him — “I will not support a nominee so lacking in the judgment, temperament and character,” says Rep. Scott Rigell of Virginia — and more suggest privately that they expect to follow.

The substantive schisms are deep. Trump’s recent foreign-policy pronouncements were derided by Sen. Lindsey Graham as a “complete disaster.” His pledge to force Mexico to pay for a wall along the southern border by withholding all remittances to that country is legally dubious, experts say, and would be an enormous expansion of executive power even as the party, and Trump himself, accuse President Barack Obama of illicitly overreaching his office’s authority.

On economics, Trump breaks with much Republican orthodoxy, except for his support for huge tax cuts for the wealthy.

Trump would not go quietly. He might try to sway delegates with various inducements, perhaps even hold out the vice presidency — his new top campaign adviser, Paul Manafort, was a player for President Gerald Ford in the 1976 convention and saw the challenger Ronald Reagan almost succeed by picking a running mate before the delegates gathered. Some Trump backers raise the threat of violence.

With the possibility of a disruptive end, Republicans are pondering how to protect incumbents at the congressional and state level. Some even argue that the best result might be to nominate someone else with Trump running as a third-party candidate, calculating that the votes he brought in would support Republicans in down-ballot contests.

That someone else would probably be Sen. Ted Cruz, who’ll come to Cleveland as the runner-up. Smart, tough, the self-proclaimed right-winger would draw a sharp ideological divide with Hillary Clinton.

Yet as the freshman Texas lawmaker gets more scrutiny, his electoral liabilities might rival Trump’s. He advocates a huge tax cut, but it would include a value-added, or national sales tax, which isn’t politically popular. He opposes all abortions without an exception for rape, and wants to roll back gay marriage rights.

Some fringe issues or elements could haunt him, too. Cruz has spoken of returning the U.S. to the gold standard. Or take a look at a recent segment by the television satirist Samantha Bee that highlighted the whacky comments of prominent right-wing pastors who back Cruz.

But unlike Trump, he’s a lifelong Republican, and while he might lose, like Barry Goldwater in 1964, the recovery might be easier.

Even as Republicans openly discuss damage control, some wistfully recall last April: They had their strongest field since 1980, the deepest bench, a favorable historical cycle against a mediocre Democratic field. That seems a lot longer than a year ago.

(c) 2016, Bloomberg View · Albert Hunt