Update: After John Kasich's campaign made clear he wouldn't appear at a Trump-less debate, Fox News Channel has canceled the event. So no more Monday debate in Utah. Michael Clemente, Fox's executive vice president for news, issued the following statement: On Feb. 20, the Republican National Committee announced that a GOP presidential primary debate would be held on March 21 in Salt Lake City. They offered that debate to Fox News Channel to host, provided there were enough candidates actively campaigning. This morning, Donald Trump announced he would not be participating in the debate. Shortly afterward, John Kasich's campaign announced that without Trump at the debate, Kasich would not participate. Ted Cruz has expressed a willingness to debate Trump or Kasich — or both. But obviously, there needs to be more than one participant. So the Salt Lake City debate is cancelled.”

Donald Trump still hasn't proclaimed himself the "presumptive" Republican presidential nominee, but his decision to skip Monday's Fox News Channel debate in Salt Lake City suggests that he is supremely confident of his eventual victory.

Recall this digital dispatch from Weekly Standard editor Bill Kristol before Super Tuesday (the first one):

That was a thinly and cryptically sourced report, but it certainly made a lot of sense. Trump boasts about "winning" every debate, but the truth is he's not at his best in these rhetorical clashes. He's not awful, but he's much better on the stump, where there are no moderators or opponents to challenge him. And debates are unpredictable — the kind of thing that a front-runner gobbling up delegates doesn't need. The real estate magnate surely doesn't want to participate in more debates than he has to; if he feels that the nomination is in the bag, or close to it, why would he volunteer for an event that won't showcase his strengths?

As it turned out, Super Tuesday was good, but not great, for Trump — not great enough to declare the race over, anyway. He submitted to two more debates, including one on Fox News that was moderated by Megyn Kelly, his least-favorite journalist. (And that's saying something, given Trump's low opinion of journalists  in general.)

But last night's primary wins in Florida, North Carolina, Illinois and maybe Missouri knocked Marco Rubio from the race and positioned Trump with more than half of the delegates needed to clinch the nomination. There's still plenty of speculation about a contested convention, but the billionaire's grip on the GOP steering wheel is very strong, at this point.

Trump announced his decision to skip the March 21 debate on "Fox and Friends" on Wednesday morning, but the writing was on the wall — or  rather, on Twitter — Tuesday night when he resumed bashing Kelly, who will once again be moderating in Utah.

Trump made an effort to lay off Kelly before and during the last Fox debate. That he no longer felt the need to feign civility indicated that he wasn't worried about facing consequences in the next one — he wouldn't be there, anyway.

The official reason for Trump's absence is a scheduling conflict. He plans to deliver a speech to the American Israel Public Affairs Committee (AIPAC).

Baloney. He could make that speech anytime. He just doesn't want to debate anymore.

Trump also claimed on "Fox and Friends" that he didn't even know about the debate. Double baloney. He said after a CNN debate last week that he was aware of plans for additional debates and that he was fine with the idea.

Trump's critics will say he's afraid of Kelly or of Ted Cruz in a three-man format with only one other rival. That might be true, in part. But the bigger reason Trump is skipping is that he simply doesn't think he needs to be there. He thinks he's already done enough to set up a general election showdown with Hillary Clinton. And he's probably right.