Where Ronald Reagan won his debates with style and quips, Mitt Romney crushed President Barack Obama on both substance and style.

Mitt Romney on Wednesday night turned in the finest debate performance of any candidate of either party in the 52 years since Richard Nixon faced John F. Kennedy, with the possible exception of Ronald Reagan’s demolition of Jimmy Carter in 1980.

But where Reagan won with style and quips — “There you go again” — and his closing line, “Are you better off now than you were four years ago?” Romney crushed Obama on both substance and style.

Mitt was like a contender so keyed up by his title shot that, between rounds, he could not sit on his stool, but stood in his corner to rush out and re-engage the champ the instant the bell sounded for the next round.

Obama was mauled, with facts, figures, anecdotes, arguments, jokes, quips. A smiling Romney was on offense all night. And the president’s performance seems inexplicable.

With the split screen showing his response to Romney’s swarm attacks, he appeared diffident, sullen, pouting, flustered, petulant.

Obama made no serious blunder. Yet, on the split screen, as Romney lectured him with a stern smile, Obama seemed a chastened schoolboy, head down, being instructed by a professor that if he did not get his grades up he would not be back next semester.

The verdict on the Denver encounter — that Romney turned in the performance of his life and one of the most impressive in the history of presidential debates, and that the president underperformed, was outclassed and lost badly — was virtually unanimous.

Indeed, liberal columnists and commentators are among those most angered and appalled at Obama’s performance.

Why did he not fight back, they ask, with all the ammunition at his disposal?

The defense being offered by the Obama spinners is that Mitt was brazenly changing positions right up there on stage, that he was not telling the truth about his positions, that he was misstating facts.

But that leaves a glaring question. Why, then, didn’t the president call him out? To this they have no answer.

Where does the race stand, a month from Election Day?

Members of the Republican commentariat who were grousing that Mitt had blown it may now become enthusiastic again, as clearly this race is far from over. Folks in the grandstand who were heading for the exit ramps are heading back to their seats.

We have a brand new ballgame here.

But if the campaign of 2012 is not lost, not by a long shot, it is not won, either.

The first sign of how great a recovery Mitt made will come next week in the head-to-head polls, when the nation has absorbed the news that Obama not only got waxed, he came off as man exhausted, weary with the duties of office, who lacks the fire and energy to lead us out of the economic doldrums in which this country finds itself.

Yet even if the national polls find Mitt surging, the polls in the battleground states will have to turn dramatically, as early voting is already taking place in half of the country. And that voting began when it appeared that Obama was coasting to a second term.

Can Ohio, for example, where Mitt has been consistently down by high single digits, be retrieved?

Is Wisconsin just too far a reach?

Perhaps the greatest advance Mitt Romney made in that debate was that, for once, he came off not just as a tough businessman and resolute budget-cutter who can put the nation’s fiscal house in order, but as something of a conservative of the heart.

This has always been the missing dimension.

The reaction of the Obamaites to the thrashing their man sustained is probably not going to be sportsmanlike. We will now hear more of the Gordon Gecko of Bain Capital writing off the 47 percent and more on the missing tax returns and Cayman Islands account.

But if we do, that will also tell the nation something.

It will testify to the truth that Barack Obama is not the nice guy he is portrayed as being. And if his campaign reverts to the low road, it will convey another unmistakable message: i.e., the president cannot win on his record; he cannot win in debates about the future. Where Reagan after his first term spoke of “Morning in America,” the only way Obama can win a second term is to demonize his opponent.

Gov. Romney still has miles to go before he sleeps. But the president is today facing a dilemma, as well.

Given his performance, one of the worst in debate history, Obama cannot afford to lose a second or third debate like that. This crushing defeat has to be shown to be, and to be seen as, an aberration.

Otherwise, the country may conclude that no matter how much it likes him, Obama as a leader is burned out, a mechanic who has tried every tool in the toolbox but cannot get the machinery running again.

The first debate made the race a toss-up again. The second could decide it.