Sigh. This was so predictable that it’s almost tiresome. The guy who attacked every Republican under the sun, no matter how small or inconsequential, who said even the least critical thing of him, has decided he’s not going to attack the Democrats who attacked him at the convention. Because, I am not kidding you, he wants to display good message discipline:

Trump recalled telling a friend this week that he wanted to retaliate against the people who slammed him at the convention, mentioning current New York City Mayor Bill de Blasio by name.

“I was going to say that de Blasio is the worst mayor in the history of the city, but I didn’t say it,” Trump said to laughs. “He’s a terrible mayor. I was going to say that, but now I won’t say it.”

Trump said his friend, who he labeled a “very great governor,” urged him to stay focused on attacking Clinton, not other Democrats.

“He said, ‘Don’t hit there. Don’t hit down. You have one person to beat. It’s Hillary Rodham Clinton,'” Trump recalled, adding that he initially objected to the advice. “I said, ‘But I really want to. I don’t like what they’re saying because a lot of it is lies. Not all of it but a lot of it is.’ I said, ‘I just really … it makes me feel good.’ ”

Ultimately, he said, he conceded and decided not to launch into verbal assaults against the Democrats.

Get the hell out of here with this nonsense, Donald Trump. Here’s the thing, right now, this is good advice. You know what? It would also have been good advice with respect to a billion Republicans who you felt absolutely no compunction about crapping all over  in the name of good message discipline.

It would also have been good advice the day after Ted Cruz gave a speech at the Republican convention that didn’t even criticize Donald Trump at all – would have been fantastic advice for Trump not to come out the next day and resurrect insane conspiracy theories about Ted Cruz’s father and promise to spend a bunch of money to beat Ted Cruz.

But isn’t it weird that Trump only discovers the joys of message discipline, not punching down, not needlessly alienating people when it comes time to attack Democrats? And by “weird,” of course, I mean, “very likely that Trump is still a Democrat who is laughing at all the Republican voters he suckered into voting for him in the primary.”

Anyway, “unity” and all that, let’s all work together to beat Hillary, which Trump visibly has no interest in doing, I guess.