Donald Trump. AP My main take-away from watching Wednesday's Commander-in-Chief Forum on MSNBC* was that Hillary Clinton will not have much trouble inducing errors by Donald Trump in their debates.

Trump did especially badly on Wednesday when he was repeatedly pressed about stupid things he had said in the past: For example, that he knows more about ISIS than the generals do, or that Vladimir Putin is "highly respected within his own country and beyond" and is "getting an A" for leadership.

Trump is incapable of disavowing such statements or effectively changing the subject. Instead, he doubles down.

By aggressively pushing back, interrupting and correcting when Trump is in the wrong, Clinton can rattle and annoy him, drawing out responses that escalate in both anger and stupidity.

Consider, for example, Trump's Miss Teen South Carolina-level word salad when pressed on whether he really has a plan to beat ISIS, a line of questioning that somehow led Trump into saying he'll probably replace much of the career leadership of the military soon after entering office:

LAUER: But yesterday, you actually told us a little bit about your plan in your speech. You said this. Quote, "We're going to convene my top generals and they will have 30 days to submit a plan for soundly and quickly defeating ISIS." So is the plan you've been hiding this whole time asking someone else for their plan?

TRUMP: No. But when I do come up with a plan that I like and that perhaps agrees with mine, or maybe doesn't — I may love what the generals come back with. I will convene ...

LAUER: But you have your own plan?

TRUMP: I have a plan. But I want to be — I don't want to — look. I have a very substantial chance of winning. Make America great again. We're going to make America great again. I have a substantial chance of winning. If I win, I don't want to broadcast to the enemy exactly what my plan is.

LAUER: But you're going to ...

TRUMP: And let me tell you, if I like maybe a combination of my plan and the generals' plan, or the generals' plan, if I like their plan, Matt, I'm not going to call you up and say, "Matt, we have a great plan." This is what Obama does. "We're going to leave Iraq on a certain day."

LAUER: But you're going to convene a panel of generals, and you've already said you know more about ISIS than those generals do.

TRUMP: Well, they'll probably be different generals, to be honest with you.

Or consider his response to a questioning about his past praise of Putin.

Asked repeatedly about this, Trump proceeded to

Praise Putin's 82% approval rating. Claim Putin called him "brilliant" (Putin says he didn't ). Say he'll say nice things about Putin as long as Putin says nice things about him. Call Putin "very much of a leader" with "very strong control over his country" (in which he has decimated the independent press and allegedly had political opponents assassinated ). Say Putin has been a far stronger leader than Barack Obama.

In both of these series of questions, Trump got more rattled, more adamant, and more bizarre as the questioning went on. And that was just under aggressive questioning by an interviewer. Imagine how he's likely to react under pressure from a political opponent.

U.S. Democratic presidential nominee Hillary Clinton arrives at the airport following a campaign Voter Registration Rally at the University of South Florida in Tampa, Florida, United States, September 6, 2016. Reuters/Brian Snyder

Remember, during the primaries, Trump allowed himself to get baited in to bragging about the size of his penis on a debate stage. This is not a man with discretion or self-control.

When I tweeted that Wednesday's forum showed Clinton should be as aggressive as possible when debating Trump, my MSNBC colleague Irin Carmon responded that this is a risky strategy for a female candidate.

Ordinarily, I would say that's true. But Trump's response to Clinton's aggression is likely to be be so overaggressive and undirected as to make her focused aggression seem measured and presidential. Plus, aggression from Clinton will help to combat Trump's charges that she lacks the "strength and stamina" to be president.

Clinton's team has already been sending signals about their intention to rattle Trump in the debates. Now we know it shouldn't be too hard for her to do so.

*Disclosure: In addition to my duties at Business Insider, I am a contributor to MSNBC, but I was not involved in the production of the forum.