U.S. Sen. Marco Rubio announced his presidential bid Monday, with the Florida Republican framing the election as a "generational choice" for Americans.
Rubio, 43, told supporters at Miami's Freedom Tower:
"Grounded by the lessons of our history, but inspired by the promise of our future, I announce my candidacy for President of the United States of America."
The freshman senator is the youngest contender in a rapidly-growing 2016 election field, but will seek to use that as his calling card in the White House campaign.
Rubio wasted no time in taking a swipe at former Secretary of State Hillary Clinton, who became the first Democratic candidate with her launch on Sunday.
"Just yesterday, a leader from yesterday," he said, as the crowd erupted in boos, "began a campaign for President by promising to take us back to yesterday."
"But yesterday is over, and we are never going back."
Now that Hillary Clinton is running for president, she can expect to hear plenty more of that refrain, but she remains the heavy favorite on the Democratic side.
There's no one else even running on that side.
The GOP side is a different story, and Rubio's candidacy will face some steep obstacles, as he's one of a half-dozen high-profile contenders already in or likely to be.
Yet the son of Cuban immigrants is optimistic, believing he offers a unique alternative to "too many of our leaders" whose "ideas are stuck in the 20th century."
"My candidacy might seem improbable to some watching from abroad," Rubio said. "In many countries, the highest office in the land is reserved for the rich and powerful."
"But I live in an exceptional country ... where even the son of a bartender and a maid can have the same dreams as those who come from power and privilege."
With his youth, political skills, compelling personal narrative and deep roots in a crucial swing state, Rubio checks off a lot of boxes ... he just needs votes.
Cruz, of Texas, and Paul, of Kentucky, are officially running to succeed Barack Obama next year. Bush and Walker are likely to throw their hats in the ring.
It's going to be an uphill battle for Rubio, who faces the challenge of maintaining GOP establishment interest while growing his appeal among conservatives.
The right is wary of Rubio for partnering with Democrats on an ultimately failed immigration reform bill, while the establishment may want a bigger name.
Yet somewhere in the middle is just where Rubio wants to be, as he hopes he can use his considerable skills to carve out a path to victory from there.