Rubio appeared on track to outperform expectations set by recent polling. ABC News projected he secured a third place spot in Iowa just behind billionaire Donald Trump.
Walking out on stage with his wife and four children, Rubio smiled as he asked a room full of supporters: “So this is the moment they said would never happen?”
In the latest Des Moines Register-Bloomberg News poll released last week, Rubio garnered the support of 15 percent of Republican voters. But Monday night, he claimed a stronger backing among Hawkeye State Republicans.
In his speech, he projected confidence.
“For months, for months they told us we had no chance. For months they told us because we offer too much optimism in a time of anger, we had no chance," he told a cheering crowd in Des Moines.
"For months they told us because we didn't have the right endorsements or the right political connections, we had no chance. They told me that we have no chance because my hair wasn't gray enough and my boots were too high.”
He added: "I thank you, we have taken the first step but an important step toward winning this election."
Rubio, who was criticized for not spending enough time in Iowa, gained momentum in the weeks leading up to the caucuses. Last weekend, the Rubio campaign aired 30 minute town hall infomercials in an ad buy that stretched across the state. And the Rubio campaign has been actively courting evangelical voters, with Rubio candidly discussing his faith at campaign events.
Rubio surged despite facing millions of dollars in targeted attack ads from Right to Rise, the super PAC supporting his former mentor and current GOP rival, Jeb Bush. In recent weeks, Bush sharpened his criticism of Rubio as his poll numbers slumped.
Rubio took note of the divisiveness in his speech on Monday night.
“When I am our nominee, we are going to unify this party, and we are going to unify the conservative movement,” Rubio said.