Donald Trump is a bully. Like most bullies when pushed back, he folds like a cheap tent. He tried to bully Paul Ryan into supporting him, saying he might remove him as convention chair. Ryan said, “Go for it” and the next thing you know, Trump wanted a meeting.

Now Trump is engaging in the same kind of nonsense with Ted Cruz as well as John Kasich. Trump told The New York Times he wouldn’t invite Senator Cruz or Governor Kasich to speak at the convention unless they endorsed him.

The response from Cruz and Kasich? Go for it:

Ted Cruz and John Kasich have a message for Donald J. Trump: They don’t care if they are not invited to speak at his convention.

That is fine, both said on Monday. A spokeswoman for Mr. Cruz, Catherine Frazier, said the Texas senator did not have any expectation about receiving a speaking slot. A spokesman for Mr. Kasich, the governor of Ohio, was similarly indifferent.

“We have not sought nor are we expecting a speaking slot at the convention,” said the spokesman, Chris Schrimpf.

Kasich said he has more important things to worry about:

Mr. Kasich’s spokesman said the governor plans to be “in and around” Cleveland that week. But he has no plans to be involved in anything that has to do with Mr. Trump.

Instead, he will attend “events focusing on keeping the Republican majorities in Congress and winning races down ballot,” Mr. Schrimpf said.

Trump did this to himself. Instead of running a campaign during the primary that elevated the debate, he decided tearing down other Republicans was the better way to go. Like a Democrat, he lied about records and engaged in the worst kind of conspiracy theories about President Bush.

Now the chickens are coming home to roost:

If Mr. Cruz and Mr. Kasich never set foot in the convention hall, they would hardly be the only Republicans staying away. Other governors, senators, members of Congress and senior party officials are skipping, too. Even some delegates are renouncing their roles.

Add to the prominent potential absences a difficulty in meeting fund-raising goals and snubs by several major corporate sponsors like Apple and Coca-Cola. Mr. Trump is running out of time to achieve his goal of a show that goes off without a hitch. It begins in three weeks.

That’s all on Donald. As I said, he did it to himself.