"It's like with the fighters," Trump told CNN's Anderson Cooper
. "If you knock 'em out, nothing can happen."
Trump said victories in Ohio and Florida would "pretty much" assure exits from Ohio Gov. John Kasich and Florida Sen. Marco Rubio.
Recent polls have shown Trump leading in both of those states, which are set to vote Tuesday.
"I think if I win those two, I think it's over," Trump said.
He also offered rationale for his victory in the Michigan Republican primary, saying his economic message resonated with the state's voters.
"Michigan has been stripped. You look at those empty factories all over the place, and nobody hits that message better than me," Trump said.
His wins on Tuesday night have left the "Never Trump" movement -- a loose collection of advocacy groups, donors and elected officials -- "mortally wounded," he said. In particular, Trump said Rubio, once envisioned as a chief Trump rival who is staking his campaign on a win in Florida next Tuesday, was seriously damaged.
Trump laid the blame on Rubio's sometimes racy attacks that he leveled at Trump after the CNN debate in Houston last week. He maintained those one-liners did not impact him psychologically.
"Nobody gets under my skin," he said. "But he was really rude. And, in fact -- for a while, I wasn't even sure if what I was seeing was right."
Trump also pushed back on a recent line of criticism lodged by Ted Cruz, who has begun to ridicule Trump's self-professed love for dealmaking and "flexibility." Cruz says that is code for Trump's ideological malleability, but Trump defended it as a way to combat dysfunction in Washington.
"If Ted Cruz became president, you wouldn't have anything done. Washington would be a total piece of stone," Trump said, bringing up Cruz's landmark legislative accomplishment -- the government shutdown spurred by an Obamacare fight in 2013. "His filibuster did nothing. What did it do? You wasted a day and a half while he sat there and told stories about 'Alice in Wonderland,' OK?"
Trump has backed a tariff of 45% on goods from China, but when pressed by Cooper, Trump said it was merely a negotiating tactic as a way to convince China to stop currency devaluation.
"When they see that we're not playing games, they're gonna stop playing with their currencies, and they're gonna stop taking our jobs to the extent that they're taking them right now," Trump said.
The real estate magnate also answered speculation about whether steaks he trotted out at his news conference
on Tuesday night are still in stores.
"Trump Steaks -- we sell the steaks through my clubs," he said. "They are available nationwide. You can buy them at different places that I own. I own many, many places."