Donald Trump. REUTERS/Jim Bourg Real-estate mogul Donald Trump had former Gov. Jeb Bush of Florida on his mind at a Monday-morning campaign event.

Trump responded to a question about political corruption by lighting into Bush, his Republican presidential rival, for trashing him on television.

"He's a total stiff, Jeb Bush," Trump said. "Here's a guy, honestly ... if he weren't in government, you wouldn't hire him to do anything, OK? You wouldn't hire him. If you had a company, you wouldn't even hire him."

Trump continued:

He's on every show: "Donald Trump said this. Donald Trump said that." And then he said, "See, I'm the only one taking on Donald Trump. I'm not afraid of Donald Trump." He's like a child. He's like a spoiled child. He spent $110 million on a campaign and he's nowhere.

Earlier in the day, Trump and Bush exchanged insults on MSNBC's "Morning Joe." Bush called Trump a "loser" and criticized other Republican candidates for not going after Trump.

Trump, the Republican front-runner, often singles out Bush at his events. At a Sunday rally in New Hampshire, for example, Trump mocked Bush for campaigning with his "mommy," former first lady Barbara Bush. The New Hampshire presidential primary is on Tuesday.

As he took questions Monday in Salem, New Hampshire, Trump further ripped into Jeb Bush for taking a more moderate position on Common Core and illegal immigration. Bush said last week that the federal government should have "no role" in the creation of educational standards, but Trump warned his supporters otherwise.

"And he's in favor of Common Core because he's not a smart man," Trump said after calling Bush a child.

Trump added:

He's in favor of Common Core. Think of it: He wants your children to be educated through Washington. And not smart. And you remember his famous statement about how … illegal immigration's "an act of love." These are the kind of people we have in government largely. I mean, he's an example of a real stiff. But these are the people we have.

"The last thing we need is another Bush," Trump said.

He continued attacking Bush throughout his event.

"You have to go out and vote tomorrow," he said at one point. "You have to do it. Because we have to get rid of the Bushes of the world. Guys like that will never straighten out this country. They'll never straighten out the country. They're weak, they're ineffective, and it's just not going to happen."

Trump later said he was friendly with most of his GOP rivals when asked whether he would appoint any of them to his administration. But he made it clear that Bush was not among them.

"I don't have a lot of respect for Jeb," Trump said. "Jeb is a lightweight, let me tell you. But I don't have a lot of respect for Jeb."

For his part, Bush fired back at Trump on Twitter: