"Two weeks from tonight, right here in Florida, we are going to send a message loud and clear," Rubio said at an event in Miami. "We are going to send a message that the party of Lincoln and Reagan and the presidency of the United States will never be held by a con artist."
But the Florida senator did manage to pick off one state: Minnesota. ABC News projected Rubio will win Minnesota's GOP caucuses, based on vote analysis
In recent days Rubio has been relentless in his criticism of Trump on the campaign trail
"Just five days ago, we began to unmask the true nature of the front-runner so far in this race," he said. "Five days ago, we began to explain to the American people that Donald Trump can a con artist."
Not long after news networks projected his win in Minnesota, the Rubio campaign sent off a fundraising e-mail to supporters.
"In the days leading up to tonight, a lot of the media had written us off. And despite the fact that we’ve shown we can win delegates all across the country, there’s no doubt they’re still going to treat me like an underdog," Rubio wrote in the note. "You know what? That’s fine: I’m happy to be an underdog. We’re a country of underdogs."