Rubio's emergence runs counter to the thinking of many observers that Jeb Bush would command a decisive and virtually insurmountable advantage in this campaign, as a result of his fundraising prowess and many endorsements from members of the party elite.
In many respects, Rubio is the perfect candidate for the party at this particular moment in history. Though the 43-year old has flaws, including very limited experience, he brings to the table a number of assets that can help him through the caucuses and primaries.
The most important of his strengths is that he contradicts the image that many Americans now have of the Republican Party: a party of older white males who are not happy about the direction of American society in the past few decades.
In part, Americans formed this opinion based on the way that Republicans have handled the issue of immigration. As the nation has become more pluralistic and diverse, with growing public support for liberalizing immigration policy, hardline conservatives in the GOP have stood in the way of progress.
Putting forth a candidate who comes from a family of immigrants will have tremendous appeal to many in the GOP, including conservatives, who want to show that their party is different than the image many have of it. This can have immense power at this crossroads moment when Republicans do have a chance to capture the White House after eight years of a Democrat in control.
Rubio's rags- to-riches story is the kind that campaign staffers love to tell.
Even one of Rubio's greatest failures, his effort to push a comprehensive immigration bill, can be interpreted as a virtue. Rubio backed a bill in the Senate that would have resolved the ongoing standoff on immigration. But he vastly underestimated the level of opposition among his House counterparts.
While the failure of the bill deprived him of a major victory, he can use his action as evidence of his commitment to resolving this key issue and his desire to govern, not just grandstand. In an era of gridlock and polarization, this will hold appeal, assuming he can get past opponents of immigration reform among GOP primary voters.
Rubio's effort to move forward on immigration can help him sell his candidacy to more moderate elements in the party at the same time that he can easily stress his credentials as a true conservative.
There is a reason that the Tea Party loved him in 2010. His opposition to Common Core standards, his deregulatory zeal, and his tough positions on Iran will allow primary voters in states like South Carolina to see that they would not be electing a moderate. He might be one of the few candidates who can sell himself in both ways, as a conservative, but also a leader who could govern.
Rubio also can project a hawkish vision of foreign policy, which still resonates in the Republican electorate, without being susceptible to the unfavorable connection people make between Jeb Bush and the controversial legacy of his brother, former President George W. Bush.
Balancing inexperience and energy
In recent weeks, the former Florida governor stumbled in response to questions about whether he would have invaded Iraq. Saying that he would have invaded, just like his brother, was definitely the wrong answer, and even Bush acknowledged as much in follow-up comments.
Bush's family connections assure that the Iraq War will continue to plague him as he contends with the more isolationist Rand Paul wing of the GOP on foreign policy.
In contrast, Rubio can more comfortably advance the three pillars of his foreign policy vision -- strong defense spending, moral clarity, and the protection of the world economy. He can do so because he doesn't stand in the shadow of the former Republican president. Still, his inability to give clear answers
about his position on the Iraq war, when being interviewed by Fox News Sunday, was a major step back in his ability to give voters confidence about his vision on international relations.
Rubio is young. Born in 1971, Rubio would bring Generation X into the White House as a 45-year-old president -- younger than Obama was when he took office -- and this would be significant for both parties. The fact is that the leadership of the Republicans and Democrats is graying.
There is a need to infuse younger voices and the ideas of those born after the turbulent divisions of the 1960s into the political arena. Until now, Democrats have done a better job engaging younger voters than Republicans.
Nominating Rubio would send a strong message that the party is moving in a new direction. The senator could speak to generational questions in way that his competitors could not.
The flip side of youth, is that opponents could tag Rubio as inexperienced, suggesting he would make some of the kinds of mistakes that people have argued took place with Obama. Yet in caucuses and primaries, as Obama learned, the energy of youth can go a long way in campaigns.
This a nation that thirsts for what is around the corner, not always what's been around for a long time. In a general campaign, Democrats would be hesitant to go too far in making an issue of Rubio's age given the age of our most recent president when he was elected.
A maverick, but not an outsider
Besides being young, the fact that Rubio did slip in recent years outside of the "frontrunner" status for the party will end up generating even more excitement about him. Even though he is in Congress, the bastion of establishment politics, he can present himself as something of an upstart and a maverick. The media loves a come-from-behind story, and so do voters.
While he can present himself in certain respects as anti-establishment, he is not. And this matters, too. Rubio has demonstrated that he can attract serious money from Super Pacs which are the new power brokers of American politics.
While he has not reached the point of Bush in terms of a network of donors he has demonstrated some pretty serious legs when it comes to campaign finance. This will be essential in the contest against the war chest that Bush is amassing. Ironically, the very positive words and support that Jeb Bush has given Rubio in the past will be extraordinarily helpful in his credibility with donors.
None of this is to diminish the weaknesses that Rubio has, including the lack of experience, or to overstate the chances that he would have of defeating Hillary Clinton. His friendship with former Rep. David Rivera
, who has been under investigation, could be an issue
on the campaign trail. The fact that he and Bush are both from Florida might divide the primary electorate and open the door for another Republican to win.
But in many respects, for Jeb Bush, and for the Democrats, Rubio is the most dangerous man in the room.