From now on, if you want to hear how Cruz is an unlikable illegal immigrant from Canada with a nasty disposition who cheated Ben Carson, has run wild like a “maniac” in the Senate, is on the take from Goldman Sachs, and, by the way, is a “pussy,” you’ll have to settle for watching Trump’s rallies or one of his 35 interviews a day on cable news.

When it comes to ads, he’s all about positivity.

On Tuesday, Donald J. Trump’s campaign started running a negative ad in South Carolina against Senator Ted Cruz that was searing, describing the winner of the Iowa Republican caucuses as a fake and a “Washington insider.”

The spot also scolded Mr. Cruz for his campaign’s role in spreading claims that Ben Carson had suspended his campaign while the caucuses were taking place; Mr. Carson, in fact, had not ended his candidacy, and Mr. Cruz later apologized to him.

But on Wednesday the spot was abruptly pulled down by the campaign. The Wall Street Journal reported on the strategic shift, saying that Mr. Trump’s campaign manager, Corey Lewandowski, had made the decision to go with all positive spots beginning on Thursday. Mr. Lewandowski made the decision after seeing that Mr. Trump’s more positive-focused tone in New Hampshire appeared to help him at the end, according to The Journal.

That’s one possibility. Trump fans may like mean Trump but undecideds who are worried about his temperament surely prefer nice Trump. Another possibility per Sean Davis is that this is just another case of Trump demonstrating his mastery of the media, knowing that his ad will get plenty of free hype now from cable news as The Ad That Even Trump Thought Was Too Negative. I think there’s probably an element too of Trump wanting to play the victim next week, knowing that Cruz has little choice but to attack him as a fake conservative, a Christian in name only, and a loose cannon. Trump likes to be seen as a counterpuncher so that he can claim self-defense when he’s accused of being a bully. He’ll probably get more mileage out of telling people “look how statesmanlike I’m being as Ted Cruz throws the kitchen sink at me” than he will from running one ad a few times on South Carolina TV. Attack ads, after all, are what politicians do, and Trump’s not supposed to be a politician. So long as he sticks to ripping Cruz to shreds in earned media rather than paid media, he’s still an “outsider,” I guess.

Speaking of ads, here’s a new one from Cruz that dropped this afternoon targeting … Marco Rubio. You can see the strategy here: To beat Trump, Cruz needs to consolidate conservatives, and plenty of conservatives are still behind Rubio. I don’t know if goofing on Rubio voters for having been naive is the best approach to conversion, though. I also don’t know how long Cruz and Rubio are planning to wait on attacking Trump in earnest while each tries to eliminate the other. Righties have been screaming at them and (especially) Jeb Bush for months to stop waging this dangerous war to become the one true Anti-Trump while Trump advances through the primaries unhindered on the assumption that there might be time to stop him later, but it looks like that’ll have to wait until Nevada, and maybe even the southern primaries, at the earliest.