"Mitt Romney is running for president because he knows that if we are willing to do for our children what our parents did for us, life in America can be better than it has ever been," the senator from Florida, considered a rising star in the Republican Party, told the excited crowd at Tampa Bay Times Forum in Tampa, Fla.
Romney's success in business is well known, but he is more than that -- husband, father, grandfather, volunteer, a member of his community and church, Rubio said.
"We are blessed that soon, he will be the president of the United States," Rubio said.
President Obama isn't a bad person -- "he's a bad president," Rubio said.
Under Obama's watch, the federal debt and deficit have grown, unemployment has risen, and new rules and regulations have been implemented, Rubio said.
Noting Obama's 2012 campaign theme is "Forward," Rubio said, "These ideas don't move us 'forward,' they take us 'backward.'
"No matter how you feel about President Obama, this election is about your future, not his. And it's not simply a choice between a Democrat and a Republican," the senator once thought to be on the short list to be Romney's running mate said. "It's a choice about what kind of country we want America to be."
Many Americans' faith has been tested during the last few years, he said.
"You want to believe we're still that place where anything is possible. But things just don't seem to be getting better," Rubio said. "And you are starting to wonder if things will ever be the same again."
America is special because it is united by common values, Rubio said, noting he watched his first Republican convention with his grandfather, who emigrated from Cuba. "Special, because we've never made the mistake of believing that we are so smart that we can rely solely on our leaders or our government."
"We're special because dreams that are impossible anywhere else come true here," Rubio said. "That's not just my story. That's your story. That's our story."
"And it's the story of a man who was born into an uncertain future in a foreign country. His family came to America to escape revolution," Rubio said. "And in November, his son, Mitt Romney, will be elected President of these United States.
"The story of our time will be written by Americans who haven't yet been born," Rubio said. "Let's make sure they write that we did our part."