By Eric Bradner

PHILADELPHIA (CNN) – Marco Rubio has won Puerto Rico’s Republican primary, CNN projects.

The win, his second campaign victory, gives the Florida senator a boost in a race that increasingly has been dominated by billionaire businessman Donald Trump and Texas Sen. Ted Cruz.

The dominant issue facing the island commonwealth — which has no electoral votes in the U.S. general election — is a public debt crisis, with the government owing $73 billion.

The results of Sunday’s primary are particularly key for Rubio, who campaigned in Puerto Rico on Saturday.

But that stop wasn’t just about Puerto Rico. Rubio’s campaign now largely hinges on taking first place in Florida’s 99-delegate, winner-take-all primary on March 15 — and the state’s Puerto Rican population could help there.

Rubio is trying to prevent Trump and Cruz from running away with the race. Through the first 19 contests, Trump has won 12 states and Cruz six — including two each on Saturday. Rubio, meanwhile, had only won Minnesota. Ohio Gov. John Kasich, whose state also holds a winner-take-all primary on March 15, is still seeking his first win.

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