HEMPSTEAD, N.Y. ― I’ve been traveling to presidential debates since 1988, and the one I just saw here at Hofstra University was historic.

Republican nominee Donald Trump turned in the worst ― and I mean worst ― debate performance in modern times. It was so bad that in a normal year, it would disqualify him from getting anywhere near the White House.

But this is 2016, a year so weird, unsettled and unsettling, that even the spectacle of an unprepared and almost incoherent Trump, reeling from blow after blow from Democrat Hillary Clinton, may not be enough to slow him down.

The electorate is divided and dug in, and the nominees are the most disliked since polling began. Even Monday’s televised mismatch may not move the numbers much. One snap poll, from PPP, showed Clinton the “winner,” 51 percent to 40 percent.

Nor is it clear that the traditional rules and pageants of electoral politics carry as much weight as they used to, especially in an era when voters are enveloped by the self-reinforcing digital news environment of their choice.

Trump landed three good blows ― on the NAFTA trade deals, the mess in the Middle East and Hillary’s history of “bad, bad experience” in public life. But in the main, he could not deal with Clinton’s well-prepared plan to attack him on every front.

As Clinton gained confidence, she flatly called Trump a racist and a sexist ― the latter with a vehemence she had clearly stored up for months. Some might have thought she overplayed her hand, but by the end of the debate Trump was hardly a sympathetic character.

With NBC moderator Lester Holt becoming more aggressive at the end after losing control of things early, the debate was for the most part an exercise in exposing Trump’s lack of knowledge and casual approach to the biggest moment of the campaign.

Trump had lame if not confusing and contradictory answers on a whole host of issues, including but not limited to: why he hadn’t released his income tax returns; the prospects and predicament of African Americans; his early business history as the son of wealth; whether he would benefit from the tax cuts he is proposing; and the role of Russia in hacking Americans.

After Holt bored in on Trump’s documented early support for the war in Iraq, the billionaire businessman was reduced to pleading with reporters to ask Sean Hannity of Fox News about supposed private conversations the two had had before the war started.

Sensing that he was losing the moment ― big time ― Trump began to blame the “mainstream” media for opposing him and siding with Clinton.

In one surpassingly bizarre exchange, he suggested that perhaps the hacker probing U.S. computer systems might be “somebody on a bed who weighs 400 pounds.” Clinton could only smile.

Rather, however, she went after Trump with all the skill of the Yale-trained lawyer she is, and did so for the most part with a wry tone that was more that of a mom talking to a 7-year-old than the public scold she is often criticized for being.

She said that she was proud that she had prepared hard for the debate ― and that to have done so was a sign of how well prepared she would be for the presidency.

That preparation including a successful effort to get under Trump’s skin, first by calling him “Donald” and then, in one particularly effective recitation, by listing reasons why Trump might not want to release his income tax returns.

Trump was left to suggest that he might release a list of banks that have extended him loans, in an effort to show that he was “extremely underleveraged.”

Some of Clinton’s prepared lines and attacks were stale and ineffective. Calling Trump’s tax plan “Trumped Up, Trickle Down” didn’t work.

She prospered more by letting Trump turn on his own spit, which he did repeatedly.

Trump also found himself agreeing with Clinton several times, like a boxer holding himself up by clutching his foe. He said that he agreed with her on the need for more generous family child care; on banning the sale of weapons to those on “no fly” lists; and on the need to do more to prevent cyberattacks.

As the debate neared its end, Holt asked Trump about his comment that Clinton did not “look” presidential. The New York businessman said that he had meant her “stamina,” not her looks.

Clinton defended her staying power by reciting her extensive travels as secretary of state and her 11 hours of testimony before a congressional hearing.

And then Clinton unloaded, saying that Trump called women “pigs, slobs and dogs” and berated a beauty pageant contestant for gaining weight.

For what it’s worth, the consensus in the press room was that Trump had been had.

And the debate reminded me of nothing so much as one of the first I covered, in Omaha, Nebraska, in 1988, when Democratic vice presidential candidate Lloyd Bentsen destroyed GOP candidate Dan Quayle with one line after the latter compared himself to President John F. Kennedy. “I knew Jack Kennedy,” Bentsen said, “and you are no Jack Kennedy.”

The debate was over that instant.

The effect on Monday was cumulative. If words matter and the rational reigns in American politics, then this would be a heavy blow to Trump’s chances.

We’ll see if it is. In the meantime, let’s not forget that Quayle ended up being vice president.

Editor’s note: Donald Trump regularly incites political violence and is a serial liar, rampant xenophobe, racist, misogynist and birther who has repeatedly pledged to ban all Muslims — 1.6 billion members of an entire religion — from entering the U.S.