Conspiracy theorist Paul Krugman speculated on Twitter Friday that President-elect Trump has an incentive to allow a major terror attack in the United States:

Thought: There was (rightly) a cloud of illegitimacy over Bush, dispelled (wrongly) by 9/11. Creates some interesting incentives for Trump

— Paul Krugman (@paulkrugman) December 16, 2016

It’s not hard to unpack this. Bush was elected in 2000 by the narrowest of margins. Less than a year later we had the worst terror attack on U.S. soil in our history. The attack caused the public to rally around President Bush. So, if President-elect Trump wanted a similar boon to his public support he might feel some incentive to follow a similar path.

How would he do this exactly? Krugman doesn’t say, probably because the whole idea is already verging on the plot of Iron Man 3 or a couple seasons of 24. Like a lot of things Krugman says, this is more about casting shade on the enemy than making any actual connection of facts. For the guy who told the world Sarah Palin was responsible for the Tucson shooting, facts are often an afterthought. The point here is simply to reinforce that Trump is a bad guy who would let terrorists kill Americans (if he could) to help his poll numbers.

Krugman went on to offer a kind of justification for his absurd theory. It’s all about Democrats taking back power through “public outrage.” That outrage should be stoked by questioning the legitimacy of the election:

Why is it useful to emphasize the questionable legitimacy of the election, not "assure a smooth transition"? Several reasons 1/

— Paul Krugman (@paulkrugman) December 16, 2016

Even if Trump can't be stopped, we need any constraints on his actions we can find — and threat of public outrage is really all there is 2/

— Paul Krugman (@paulkrugman) December 16, 2016

Plus anything that enhances future chance of turnaround is essential — which means not forgetting and normalizing the subversion of 2016 3/

— Paul Krugman (@paulkrugman) December 16, 2016

You can't put this back in the box, and trying to do so just makes the horror of the situation worse 4/

— Paul Krugman (@paulkrugman) December 16, 2016

Krugman has been saying for weeks that Trump’s victory was illegitimate. Back in October after Director Comey announced he was looking into additional emails found on Anthony Weiner’s laptop, Krugman tweeted that Comey was probably trying to swing the election or, at a minimum, help Republicans hold the Senate.