Story highlights Donald Trump leads Marco Rubio by 8 percentage points in Florida, a new poll shows

Florida holds its critical winner-take-all primary on March 15

(CNN) Donald Trump is leading Marco Rubio in the Florida senator's home state by 8 percentage points, a Monmouth University poll out Monday shows.

Trump has the support of 38% of Florida's likely GOP primary voters, compared to 30% who back Rubio, 17% for Texas Sen. Ted Cruz and 10% for Ohio Gov. John Kasich.

The snapshot of Florida comes before the state's crucial 99-delegate, winner-take-all primary set for March 15.

It's a must-win for Rubio, who has fallen behind Trump and Cruz in the delegate race after taking only two of the first 20 Republican contests.

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