New York’s Vote Matters for a Change Trump tries to recover from his Wisconsin deflation, while Sanders finally gets aggressive.

In Wisconsin and in the weeks leading up to it Donald Trump got wounded. Big animals get wounded and come back. The question is whether he’s a big animal or something smaller that skittered around the forest and finally picked the wrong fight.

Wisconsin almost certainly foreclosed his chance to walk into Cleveland with enough delegates to win on the first ballot. The convention will be open, and contested.

There’s nothing easy about Mr. Trump. He leaves his supporters’ hearts in their mouths. He leaves his enemies happy then self-doubting, triumphant then fatalistic. But what we have witnessed the past few weeks is his deflation, a real one, and the worst kind: It was all his fault. It wasn’t the anti-Trump forces and it wasn’t Ted Cruz, it was his lax, louche indiscipline.

But now we cut to New York. We are about to witness something of a Trump reinflation.

Donald Trump

Donald Trump

The other night he drew some 10,000 people to a rally in Bethpage, Long Island, which the Daily News called “riotous” and Newsday called “rousing.” I lived in Long Island from age 5 to 16 and go there often. My friends and their children are a generation or two from Brooklyn and Queens, and Brooklyn and Queens were one or two generations from the old country. Long Islanders carry within them, still and more than they know, a love for America tinged by family lore of the immigrant experience—an old and patriotic sense that gets mixed up, in the current way, with a nationalistic sense. Republicans who were amusing themselves on social media the night of the rally—as word spread of turnout they were sending out pictures of Joey Buttafuoco—look down on those rally-goers at their peril. They will be part of the base of whatever takes the place of the current Republican Party.

Mr. Trump, in the video I saw, was masterly. “We don’t win anymore,” he said. “We don’t fight like people from Long Island. We don’t fight like people from New York.” He laid into Mr. Cruz: “Remember when he started lecturing me on ‘New York values’ like we’re no good?” That was the authentic sound of working New York: “Like we’re no good.”

And it felt fresh, because no one really campaigns for the presidency in New York anymore. Its primaries are in April, usually after everything’s been settled. In the general election New York’s in the bag for the Democrats, so why should they expend the energy or Republicans the time?

Candidates for president only come here for major media interviews and for money. They pick Manhattan up and shake it like a big pink piggy bank—$60K at the downtown breakfast, $600K at the uptown cocktail party. They enter the homes of the great and powerful—the spacious rooms, high ceilings, plump sofas, shiny floors, important art, views of Central Park—and they think: “Boy, they sure got it good. Maybe the economy isn’t so bad!”

The rich of New York thus hold an outsize place in the Republican and Democratic imagination. But the not-rich—the middle, the hanging-on and the poor—have no place at all.

Republicans especially, the past 20 or so years, have no sense of them. They know the hedge-funders and the rooms with the Rothkos. Their vision of everything else comes from old movies like “Dog Day Afternoon.” They’re surprised we’re not all running around in the streets shouting “Attica! Attica!”

What Republicans especially fail to appreciate is that New York more than ever is full of legal immigrants. If you sit on the side of a street fair in non-hipster Brooklyn—in Bay Ridge, for instance—you’ll see all the world passing by: people from China, Ireland, Lebanon, Poland, South and Central America, Asia, Africa, Arabia. They are young. They’re expending all their energy doing what people do to establish themselves—finding the job, keeping it, paying the rent, finding someone to love, making a family, making it all work.

So far they have no time for politics—but they will. They’re not aligned—but they will be. They are open to persuasion. They will consider your argument. All you have to do is be there and talk to them. If the Republican Party were thinking long-term, it would. Maybe when the party is reconstituting itself—trying to rebuild a damaged or destroyed party, or inventing a new one—they’ll recognize these people too as a potential part of their base.

In any case Mr. Trump is expected to win big. He’s 31 points ahead in the polls. Is there any chance he can discipline himself and sustain the discipline, create a real campaign, professionalize his operation? Would it make a difference? Or are his reputation and his mess set so firmly in concrete nothing can change his outcome?

On the Democratic side Bernie Sanders has turned tough. He seems to have come face to face with the fact that he really wants to win. He said Hillary Clinton is not “qualified” to be president because of her support for the Iraq war, “disastrous” trade policies, and taking Wall Street money. His campaign manager, Jeff Weaver, upped the ante by saying if Mrs. Clinton hits back unfairly, “they’re going to see how a real New Yorker fights back.”

God bless New York for stripping the passive from the passive-aggressive campaign they were waging against each other until this week.

I saw Mrs. Clinton at Harlem’s Apollo Theater last week. The audience was appropriately enthusiastic but not wild. Soon after, I watched the Sanders rally in the Bronx—a crowd of at least 15,000 that was wild. A Hillary supporter I spoke to at the Apollo confessed she was there to reignite her excitement. In her life she was surrounded by Bernie supporters. It leaves you feeling defensive.

If he dings her bad or wins in New York it will be a real setback for Mrs. Clinton, and an embarrassment.

Everything on both sides is still so in play.

Washington Republicans continue their fantasy of the white knight who comes to Cleveland and saves the day—the magical unifying figure who electrifies the convention and wins on the fourth ballot. But how would the large majority of Republicans who’ve voted for Mr. Trump or Mr. Cruz feel about that? Not good!

Again, if Mr. Trump wins, a significant part of the party splits off. If he doesn’t, a significant part of the party likely isn’t there in November. I was asked this week if Trump always intended to break the party. I don’t think so; I think he set out to win. But whether he wins or not he has succeeded in demonstrating to the party that it is and was broken. He made the information unavoidable.

A friend with whom I’d been discussing the convention, a former Romney bundler, this week sent me a gift: handsome two-inch heels, heavily padded on the sole so if there is trouble you could run in them. The outside fabric is rough camouflage, the kind a soldier would wear in the field.

That’s a fellow whose fantasy of what the convention will be like is probably closer to the mark.