In the lead-up to Tuesday's 99-delegate, winner-take-all Florida primary, Trump leads Florida Sen. Marco Rubio by 17 percentage points in the lawmaker's home state, according to the RealClear Politics polling aggregator.
Rubio's support has been recently fading — exemplified by a string of weak performances in the latest nominating contests.
Ohio, with 66 winner-take-all delegates up for grabs, also holds its primary Tuesday, and Trump has a narrow 2.5 percentage point lead over Ohio Gov. John Kasich there, according to the latest polls.
"I think I have a good shot in Ohio. And I have a much better than good shot in Florida," Trump predicted, saying he created many jobs in Florida through his business ventures and owns a lot of property there.
Kasich, with billionaire Wall Street backers Stanley Druckenmiller and Ken Langone, hopes to win his home state and jumpstart his struggling campaign. Kasich is dead last in the delegate count, behind Trump, Cruz and Rubio.
Trump said it's too early in the race to talk about a vice presidential running mate.
Speculation has swirled around whether Chris Christie might be on the short-list, after the New Jersey governor and former GOP presidential candidate endorsed Trump last week.
"Chris is a good man," Trump said. "[But] it's too early." He added he'd pick "somebody very good" when the time is right.
Trump refused to speculate on what a two-man race with Cruz might look like. "Who knows what happens. It's politics. It's crazier than business."