Analysis by Chris Cillizza, CNN Editor-at-large

(CNN) -- Hours before Donald Trump was set to face off for the last time against Joe Biden on the debate stage, the President handed his challenger an attack on a silver platter.

"I hope that they end it," Trump told Lesley Stahl of "60 Minutes" about the Supreme Court's consideration of the constitutionality of the Affordable Care Act next month. "It'll be so good if they end it."

Asked by Stahl what would happen if that happened, Trump responded that he has a replacement plan ready to go. "It's fully developed," he insisted. "It's going to be announced very soon, when we see what happens with Obamacare." (Fact check: There is no plan.)

When pressed on details of this (nonexistent) plan by Stahl, this exchange occurred:

Stahl: What about people with preexisting conditions?

Trump: I'll protect it. Will be totally protected.

Stahl: How?

Trump: They'll be protected, Lesley.

Stahl: How?

Trump: I mean the people with preexisting conditions are going to be protected.

Stahl: How?

Trump: As they are now.

Stahl: How?

Biden couldn't have written a better script himself. He has repeatedly attacked Trump for his support of getting rid of the ACA -- and asked people to consider what that entails.

"Now, what's at stake here is the President's made it clear, he wants to get rid of the Affordable Care Act," Biden said in the first debate. "He's been running on that. He ran on that and he's been governing on that."

Now Biden can point to Trump's responses to Stahl -- about both the ACA and the alleged replacement plan -- as evidence that not only does Trump want to knock out the current health care law but he also has nothing to replace it with. Which means people will be left without coverage. Lots of people.

And why? Why did Trump hand Biden such a potent issue hours before the debate? Because he released 37 minutes of unedited video of his interview as evidence of the "bias, hatred and rudeness on behalf of 60 Minutes and CBS." (It wasn't. It was evidence of a real reporter asking real questions -- and following up.)

Because of Trump's obsession with proving his point, he just opened himself up to an easy attack -- on an issue that impacts lots and lots of people -- by Biden in tonight's debate.

The Point: Strategy? Please. This is just Trump saying stuff. And often in ways that directly -- and negatively -- impact his chances in this debate and the race more generally.