The Ohio governor is leading Trump in his home state, 34%-29%, according to one of the polls
, with a strong bump from Republicans who overwhelmingly approve of his job performance there.
But in Florida, Trump has more than double the support of home-state Sen. Marco Rubio, 43%-20%, according to another poll
. The broad support for Trump in Florida is driven by a feeling that voters have been "betrayed" by their party -- a sentiment consistent with most exit polling from previous Republican contests.
The two states could determine who the Republican nominee is.
Trump predicted Wednesday that if he wins both states, he will be unstoppable on his path to the Republican nomination. Both states are winner-take-all contests and have been the focus of much spending from the campaign to stop Trump, which is being led by 2012 nominee Mitt Romney and top Republican donors and staffers.
But recent polling has been mixed for both sides, showing Trump with big leads in Florida, but running a tight race with Kasich in Ohio. Texas Sen. Ted Cruz has emerged as the chief contender with Trump for the nomination, but he is running in third in both states, according to the new Fox polls, with 19% in Ohio and 16% in Florida.
Fox News' Florida poll was conducted with 813 likely Republican voters in Florida from March 5-8 and carries a margin of error of plus or minus 3.5 percentage points.
Fox News' Ohio poll was conducted with 806 likely Republican voters in Ohio from March 5-8 and carries a margin of error of plus or minus 3.5 percentage points.