Washington (CNN) For all of Donald Trump's struggles in his first 19 months as President, there's one thing he's proven particularly adept at: Picking winners in contested GOP primaries.

That run of winners continued Tuesday night when voters went to the polls in Arizona and Florida

The most obvious example of Trump's power within the party is in the Florida governor's race, where, late last year, he tweeted favorably about the candidacy of Rep. Ron DeSantis, who was seen as a heavy underdog to state Agriculture Commissioner Adam Putnam in the primary.

"Congressman Ron DeSantis is a brilliant young leader, Yale and then Harvard Law, who would make a GREAT Governor of Florida," Trump tweeted just days before Christmas . "He loves our Country and is a true FIGHTER!"

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