From last night’s speech to the New England Police Benevolent Association, which voted to endorse him. Rarely can you tell whether a new Trump policy idea was gamed out beforehand or just something he came up with on the fly while in front of a mic, and this is no exception. His advisor, Dan Scavino, tweeted it out after Trump said it, though, so if it wasn’t official campaign policy before, I guess it is now.

Is it worth critiquing this? Krauthammer’s ready to give up on arguing against Trump policies, partly because they’re all obviously political panders rather than serious proposals and partly because pointing out that the policy is dumb and/or illegal only seems to make Trump fans want to spite the critic by embracing the idea more tightly. Besides, anyone who’s been following the last few years of Obama’s executive overreach already sees the problems here. For starters, cop-killer prosecutions usually fall under state, not federal, jurisdiction. Nineteen states have abolished the death penalty entirely, including Trump’s home state of New York. The idea that the president can dictate to a state how it should punish its criminals is a kick in the nuts to federalism so sharp that even Obama wouldn’t try it.

Meanwhile, at the federal level, sentencing is a matter of congressional legislation, not presidential decree. Maybe Congress could set some kind of default of death in cases where an FBI agent is murdered, with the burden falling on the defendant to explain why it isn’t merited. Legal eagles would know better than I about that, but my hunch is that courts would look coldly at a law that tips the scales towards death after a guilty verdict rather than allowing the jury to consider aggravating and mitigating factors prevented by the two sides. The most President Trump could do legally on his own, if I’m not mistaken, is to order the DOJ to seek death in any trial where the defendant is charged with a capital offense. But even that would meet some resistance. The DOJ answers to the president but they’re also supposed to be insulated from political pressure. What Trump’s suggesting is that he’d take away their prosecutorial discretion (kind of like Obama did with executive amnesty!) and order them to choose a particular sentence in a certain class of cases. And not just any cases but the ones with the most at stake for the defendant.

That’s the best-case scenario of what he’s proposing. The worst case, depending on how seriously you take him when he says “the death penalty is going to happen,” is that he wants to take sentencing out of the hands of juries altogether in cop-killing cases and put it in his own hands. The jury thinks there are reasons to sentence this cop-killer to life? Too bad. President Trump has spoken. Pretty sure courts would be cool to that idea too.

But what does it matter? You know how this will go now. Jonah Goldberg explained it the other day:

Trump says something indefensible, half-baked, or otherwise ridiculous. He then walks it back slightly or — as he did with taking-in Syrian refugees — entirely. His defenders take the revised version of what he said at face value, add in a serious point or two that Trump has not actually made, and then make it sound like his critics are the unreasonable ones.

A reporter will ask him about this in their next interview and he’ll say, “Well, if I can’t order the death penalty, I’ll recommend it.” And Trump fans will say, “See? He was never talking about mandating it!” And then Rush will do 20 minutes on that day’s show about what a master media manipulator Trump is and how this affront to federalism and separation of powers is a drop in the bucket compared to what Obama’s guilty of.

Exit question: How often do DAs in states where the death penalty is legal decide not to seek death in cases where a cop is murdered? Pretty rarely, no? Why do we need President Trump to order a policy that’s already basically in effect?