Donald Trump’s five-state, 110-delegate triumph Tuesday in the “Acela primary” sweep may have been expected, since his only real competition, Senator Cruz, had conceded much of the territory as too unwelcoming to warrant investment. The back-to-back victories taking place on the national press’s home turf were bound to be magnified.

All the more dramatic the fact that the race has emerged at only even odds that Mr. Trump gains the nomination. Today he has about 955 bound delegates and needs almost 300 of the 500 bound delegates at stake in the remaining primaries, many on territory not nearly so inviting. While ABC News reports that a majority Pennsylvania’s 54 unbound delegates have declared for Mr. Trump, they can undeclare quite easily, so Mr. Trump is not there yet, mathematically.

However, at least psychologically, the billionaire is an overwhelming favorite. Mr. Cruz faces a challenge of Mount Everest proportions; Carly Fiorina is a helpful start. The Texan must make a case to voters so that they will resist the tendency to hop aboard a bandwagon. Too, he needs to convince voters to cast strategic ballots enabling him to block Mr. Trump so that their favorite, some other candidate, can prevail at an open convention. Few people vote strategically.

Governor Kasich won only five delegates yesterday in a region he had claimed was his turf. If ever his candidacy had any rationale or purpose, it disappeared yesterday. After yesterday, there’s little strategy in voting to preserve a lifeless candidacy. And that brings us to Indiana and its trove of 57 bound delegates.

As part of the recently-struck Cruz-Kasich alliance to stop Trump, Mr. Kasich has bowed out in favor of Senator Cruz — sort of. He cancelled public appearances and campaign ads, but said his Indiana supporters should still vote for him. Nevertheless, beforehand the two were competitors splitting and diluting the anti-Trump vote; now, they are allies optimizing and strengthening it. There’s value in that, if not much.

In Indiana, Mr. Trump held only a 6 point lead over Mr. Cruz in the Real Clear Politics average of polls predating his sweep yesterday and predating the alliance, and it included 19% for Governor Kasich. If Kasich supporters follow their candidate’s signal and switch to the Texan, that lead reverses. Not that the Kasich crew sees Mr. Cruz as much better than Mr. Trump, who’s been endorsed by the Hoosiers’ legendary basketball coach, Bobby Knight.

No matter the polls, Mr. Cruz needs to win the Hoosier State to blunt Mr. Trump’s momentum and rebalance the psychology of the race. By winning the state, he would win 30 statewide delegates outright and, logically, take most of the delegates in the state’s nine congressional districts. The Indiana winner will take from between 45 and 57 of its delegates.

The following week, the Texan is heavily favored at Nebraska, where all 38 bound delegates go to the statewide winner (there are no district-level contests). If Mr. Cruz prevails, his Indiana-Nebraska delegate haul will largely offset the billionaire’s bound-delegate sweep Tuesday, sustaining the mathematical and psychological life of his campaign and the stop-Trump forces.

Since Mr. Cruz is heavily favored to win 59 bound delegates in the winner-takes-all contests in South Dakota and Montana on June 7, the New Yorker would face his own daunting challenge: needing almost 300 bound delegates from a shrunken pool of as little as 345.

That’s the delegate math. The more important challenge for Mr. Cruz is to embrace the central reality of Trumpism, namely that Mr. Trump has tapped into a bedrock concern that the GOP has failed to acknowledge. The GOP is the party of capitalism, free trade, and globalism, which proponents credit with having lifted billions out of poverty around the world over the last quarter century.

That’s means little to American blue collar workers whom those same forces have pushed into poverty, as their jobs have gone overseas. Hence Mr. Trump’s vow that these forces must be tamed to protect American workers. Mr. Cruz bromides about being a “constitutional conservative” pale in comparison to the economic concerns of angry and alienated GOP primary voters.

They want a plan to generate real jobs, not low-wage “service economy” jobs. The Texan has one week to reformulate his message. He needs to speak from his heart about the crisis in blue collar America. He needs to explain that Mr. Trump doesn’t offer any solutions, only off-the-cuff bluster about “15% tariffs” and “making better deals.”

Senator Cruz should embrace the legendary rallying cry of the 1975 Islanders hockey squad. After having lost the first three games in their best-of-seven Stanley Cup playoff round, they bellowed defiantly: “we’ve got them right where we want them.”

RTJahncke@Gmail.com. @RedJahncke.