Athens - Florida Sen. Marco Rubio told Georgia Republican delegates Friday he would overhaul the higher education system and offer a more muscular foreign policy to counter growing international threats.

"The Cold War is over, but that doesn't mean the world doesn't need American leadership," said Rubio.

The Florida Republican was one of three presidential candidates to make a pilgrimage to the GOP convention Friday to appeal to delegates. New Jersey Gov. Chris Christie spoke earlier, and Texas Sen. Ted Cruz was set to keynote a dinner Friday evening.

Rubio told the crowd that he would encourage more students to go into vocational fields and offer more pathways for non-traditional students to get college degrees.

"We need competition in higher education. We need choices in higher education so that people who are working full time and also raising a family can receive a certificate."

In an interview after the speech, Rubio sought to downplay questions about his lack of experience. He was elected to the Senate in 2010 after serving as Florida's House speaker.

"The most important quality of a president is the ability to make important judgment calls, and the four years I've been in the U.S. Senate has shown my ability to do that."

He added: "This election is not about what someone did yesterday. It's about what we do tomorrow."

As for the growing crowd of Republicans in the race - Texas Gov. Rick Perry's camp said Friday he would join the field in June - Rubio said the competition was welcome.

"We have a talented pool of people and from it we'll have a better nominee. Competition breeds excellence," he said. "Republicans should be happy there are so many candidates. Democrats are struggling just to have one."