(CNN) Sen. Marco Rubio of Florida is in serious danger of losing his home state to Republican presidential rival Donald Trump, a new poll shows.

The survey shows Florida voters are beginning to make up their minds: Only 5% of likely Republican primary voters said they are undecided, though 30% say they may change which candidate they support.

The Florida GOP primary, which awards the winner all of its 99 delegates, will take place March 15.

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