Via the Free Beacon, we’ve reached the stage of Trumpmania where the same media that used to routinely predict that every new Trump “gaffe” would finish him off now heralds everything Trump does as carefully calculated Machiavellian genius. Trump has convinced them to their bones, not without reason, that everything they thought they knew about presidential politics is wrong and every move he makes is right. Case in point: Skipping the debate four days before Iowans caucus is genius. Why? Because Trump’s a genius and he thinks it’s a good idea, even though there are lots of really obvious perils in a move like that. Same goes for this attack on Cruz, I assume. Suggesting that Cruz isn’t a U.S. citizen at all because he wasn’t born here is genius. Why? Well, Trump thinks it’s genius, and he has had success in driving Cruz’s favorable numbers down in Iowa this month by questioning his eligibility. Case closed, right?

Let’s think strategically. Assume you’re Trump and you’ve just won Iowa. Who are you worried about now? Answer: Whoever looks to be the strongest center-right contender in New Hampshire. That’s probably Marco Rubio, especially if he finishes strong in Iowa, which he may well do. The special danger that Rubio poses, not just to Trump but to everyone, is that he can pull from both sides of the field as others drop out. Some conservatives will never support him because of amnesty, but some will. And plenty of moderates will. If Trump is headed for a two-man race with Rubio then he should be thinking already about how to lure Cruz’s voters, some of whom are open to Trump because he’s a populist but some of whom are open to Rubio because he’s more conservative than Trump is. Trump should want to do everything he can to tear down Cruz at this point by attacking his record without doing something that angers persuadable Cruz fans so much that they opt for Rubio over Trump out of spite if forced to choose. (Cruz doesn’t have the same problem with Trump fans. None of them are going to Rubio if the race comes down to Rubio and Cruz, so even if Cruz alienates them, the worst thing they’ll do to him is stay home.)

Accusing Cruz of being an “anchor baby” in Canada and of possibly not even being a U.S. citizen is, I think, the sort of attack that’ll alienate Cruz voters more than garden-variety stuff like “Cruz doesn’t play well with others.” It’s dirty pool in a way that attacks on his record in the Senate aren’t. What Trump’s doing here is suggesting that the “natural-born” clause in Article II isn’t just a qualification for the presidency but a bright-line rule for citizenship generally. If you were born on U.S. soil, Trump’s hinting, you’re a citizen. If you weren’t, and weren’t later naturalized, you aren’t. That’s not true, though: Congress sets the rules for citizenship, and there’s no question that Cruz qualified per the statute that was in effect when he was born in 1970. The only question is whether he can lawfully run for this office under the Constitution. By conflating those two ideas, citizenship and Article II eligibility, Trump’s basically accusing Cruz of being — ta da — an illegal immigrant. And not just an illegal immigrant, but an illegal immigrant in two different countries. That’s what the “anchor baby” business is all about: I’ve never read anything suggesting that Cruz’s parents were in Canada illegally when he was born and used his birth as a way to establish legal residency, but that’s what most people think of when they think of “anchor babies.” (An “anchor baby” could also be used by legal residents to extend their legal residency in a country.) “Anchor baby” is doubly stupid as applied to Cruz since his parents didn’t actually use him as a long-term anchor in Canada. They moved to the U.S., of which his mother is a citizen, when he was a toddler. Trump’s essentially down to arguing that not only is Cruz weak on amnesty, he is amnesty. If he ends up losing the caucuses and fades from the race, I wonder how it’ll sit with Cruz to think that Trump outmaneuvered him by questioning his loyalty to America and even his right to be here. Once upon a time, I thought he’d endorse Trump if he dropped out as part of a broad populist offensive against “the establishment.” Now I wonder.