Karl Rove, in his calamitous career, got one thing right: attack the other guy’s strength. That’s what Hillary Clinton should do to Donald Trump, starting yesterday.

What are Trump’s perceived strengths, especially among swing voters who might consider voting for him? The first is that he’s a businessman. All kinds of people (who have no idea how inefficiently most businesses are run) say they want someone who can run the government like a business. The second is that he’s a tough guy. He talks tough, about ISIS and terrorists and what not.

I submit that if you take those two points away from the guy, he’s finished. Fired. Another loser.

On the business business: Sure, start with the bankruptcies, the casino failure, Trump Air, all that. There’s fodder there. But I don’t even mean that stuff particularly. We know his answer to those things: I used bankruptcy laws to my advantage like any businessman would. It’s not implausible.

No, I really mean this. There are business leaders out there, corporate leaders, who are mortified at the thought of Donald Trump occupying the Oval Office. Because he’s crazy. A loose cannon. Because he has no idea of what he’s talking about. Because he assumes he can just will things into being. Because he thinks he can slap a huge tariff on China, and China will just take it, and not retaliate with tariffs of its own on our exports that will destroy jobs and wreck our economy. (Value of U.S. exports to China: about $120 billion a year.)

What’s the word corporate America keeps using against Washington? That our dysfunctional government isn’t providing “certainty.” Trump is uncertainty to the power of n. Plus he’s just embarrassing.

These people—and I don’t mean Wall Street, I mean the people who run businesses that make or package or ship things, and people who work in executive suites—are Republicans. And they always vote for the Republican. You might remember from 2012 that a number of CEOs implored their employees to vote for Mitt Romney to save America from the socialistic path down which Obama had led it. One boss even said his employees might suffer “personal consequences” if they voted for Obama. To the C-suite crowd, Romney was one of them.

Trump is not. Trump’s a huckster. Nobody knows it better than these people. The Clinton campaign ought to get as many of these folks as it can to go on the record or appear in an ad saying that while they may not be the world’s biggest Hillary fans, the thought of Donald Trump sitting in the Oval Office makes them want to relocate their business to Mogadishu.

Now, with regard to the tough-guy stuff. The way to shred that calling card is with the military. This may surprise you at first blush. Surely, you think, military types will prefer Trump to Clinton! He’s a man. He talks tough. He’s not gonna pussyfoot around with ISIS the way those Democrats always do.

If you think this, I implore you to read “Trump at War” by Andy Kroll. It’s about how military people are terrified at the thought of Trump becoming their commander-in-chief, because they think he knows nothing about their line of work and they fear that someone who talks like he does without understanding the consequences will start World War III. Some people quoted in the article spoke openly of having to disobey President Trump’s orders, which is not only permissible but called for when an officer believes that a president’s orders violate code and law.

“You bet your ass” I’d reinstitute water-boarding, Trump has said. Military and intelligence professionals are the last people in the world who want that. It violated international law, which most of them actually care about. And the controversy over it crushed morale. A former CIA general counsel told Kroll that if President Trump ordered water-boarding and other forms of torture, staff would abandon the agency. “At a minimum,” the lawyer said, “people would refuse to participate in anything resembling the former interrogation program and insist on a transfer to another part of the agency where they wouldn’t be involved in these things.”

Conversely, more military people than you’d expect kind of respect Clinton. No, not because she voted for the Iraq War. Because she sat on the Senate Armed Services Committee and got to know their issues. Knows the difference between a brigade and a regiment. Put in ample face time as senator at New York’s military bases. They respect her.

Now under normal circumstances I doubt most brass would vote for her. But these aren’t normal circumstances.

We have a truly dangerous and borderline sociopathic man who has shown that he knows nothing about military structure and is casually proud of his ignorance—but who may be running it. This will horrify many active and retired military people. The actives have to stay silent, but the Clinton campaign ought to be able to find plenty of retireds who’ll say they basically trust her to treat the military right, while he doesn’t belong within a par-five fairway of the nuclear football.

Business people are scared of him, military people are worried sick about him. Aggressive ads and other forms of attack along these lines will make it clear to middle-of-the-road voters that, however they may feel about Clinton, Trump is simply not an option. Coming from those two groups, the message would carry a lot of weight.

His two strengths—which are not actual strengths but myths he has fashioned about himself—will disappear.