Florida Sen. Marco Rubio, who told donors Monday that he will run for president and who will hold a formal announcement rally later Monday afternoon, will enter the 2016 race as the candidate with perhaps the widest range of potential outcomes. There is a plausible path for Rubio to be elected president in 2016, but also one in which he loses the GOP primary without carrying a single state.
Since Rubio came to the Senate in 2011, Republicans and the press have been touting him as a future presidential candidate. Republican elites say the Florida senator is the best public speaker in the field.
He would make history if he were elected, becoming the first Latino president. His youth (Rubio is 43) offers an obvious contrast with both Jeb Bush (62) and Hillary Clinton (67). He is well-liked by the party's moderates, establishment and donors, unlike Texas Sen. Ted Cruz and Kentucky Sen. Rand Paul, his two Senate colleagues who also have officially announced their candidacies.
On the other hand, Rubio has not finished his first term in the Senate and has no executive experience in either business or in government. And he must get past Bush, who is a well-known figure in the Republican Party and the early front-runner in the nomination process.
So at least in general terms, Rubio has a lot of political similarities to Barack Obama in 2007. And Bush is not dissimilar to Clinton in 2007: a front-runner who is vulnerable both because of issue positions (Iraq for Clinton, immigration for Bush) and because some in the party are weary of picking the dynastic candidate.
Rubio has the same kind of opportunity Obama did to beat the front-runner by running as a youthful, optimistic candidate of the future.
The Republican Party, though, has strongly opposed Obama's tenure and argued that his lack of executive experience before entering office was a huge flaw that has plagued his tenure. Republicans don't want to tap the conservative equivalent of Barack Obama as their nominee.
So right now, Rubio's lack of experience and his youth are huge barriers that are limiting him from getting the kind of early support that Obama enjoyed in his 2008 campaign.
The former Senate Majority Leader, Tom Daschle, endorsed Obama in February 2007, backing that solidified the belief that Obama was a viable Democratic presidential candidate.
It would help Rubio greatly if some veteran former leaders in the GOP endorsed him, vouching for his readiness to be president. The Washington Post reported last month that Rubio has impressed Mitt Romney in private discussions.
But it seems unlikely that figures like Romney or Arizona Sen. John McCain will endorse Rubio early in the race. The party's veteran leaders are for now either endorsing Bush or not picking anyone at this stage.
And Rubio, by co-writing a bill in 2013 supported by Obama that creates a pathway to citizenship for undocumented immigrants, weakened his ability to woo very conservative voters, another key bloc in the GOP primary.
Rubio was one of the Tea Party's favorite candidates in 2010, when he defeated Republican moderate Charlie Crist in the Florida U.S. Senate race. Now, as Rubio enters the presidential race, those conservatives are looking at other hopefuls, like Cruz and Paul.
How can Rubio win? The state-by-state path looks very difficult for him. Candidates like Cruz and Gov. Scott Walker of Wisconsin may have more appeal to the evangelicals and conservatives who dominate the Iowa caucuses, particularly since Rubio wrote an immigration bill that Cruz strongly opposed. New Hampshire, which votes second, has more moderate Republicans who could favor Bush.
Rubio has no obvious advantage in Nevada or South Carolina, the other two early states in the GOP primary.
With Bush in the race, Rubio is not even guaranteed of winning his home state of Florida.
But Republican voters in all parts of the party feel Rubio is someone they could support, even if he is not currently their first choice.
Rubio is to the right of Bush on some issues, such as opposing the Common Core education standards that the former Florida governor has supported. Rubio's years in the Senate have given him the ability to speak more fluently on domestic and foreign policy than Walker, who in the early stages of race has struggled to answer basic questions on many issues. Moderate Republicans are deeply skeptical of Cruz, viewing him as too conservative to win the general election.
Because of his broad acceptability, it's easy to imagine Rubio becoming either the anti-Bush candidate, appealing to conservatives wary of the ex-Florida governor, or as the more moderate alternative to Cruz or another candidate more closely aligned with the Tea Party.
Bush is currently the favorite of moderate Republicans, and Walker the leading alternative to Bush among conservatives. So Rubio probably needs either Bush or Walker to falter to win.
But that is entirely possible. Bush last won an election in 2002, and many Republicans view him as a flawed candidate for the general election because of his last name and his brother's controversial tenure. Walker is untested in national politics.
Many Republican elites currently say the party should choose a governor who has executive experience, but they could still opt to back Rubio over New Jersey Gov. Chris Christie and Ohio Gov. John Kasich, both of whom have reputations for being prickly and have also taken liberal stances at times. (Both Christie and Kasich expanded Medicaid in their state as part of implementing Obamacare.)
Rubio is likely to benefit from the campaign process in Iowa and New Hampshire, which requires meeting with small groups of voters in tiny towns. The Florida senator is affable and personable, like Obama. He has delighted conservatives with his strong opposition to Obama's moves to normalize relations with Cuba and reach a nuclear weapons agreement with Iran.
In 2008, Obama won Iowa, and everything changed for him. His victory showed Democrats that he could beat Clinton, and that caused both voters and key elites like Ted Kennedy to get behind him. Romney for example has tense relations with Bush. If Rubio won Iowa, it's easy to see Romney then endorsing the Florida senator, which might cause other key Republicans to do so as well.
If Rubio won the primary, the path to the presidency would still be challenging. There is no evidence Latinos, about 70 percent of whom backed Obama in 2012, will shift to the GOP simply because it has a Latino nominee. And while Latinos are often lumped together, Cuban-Americans tend to more conservative and Republican-leaning than Mexican-Americans. It's not clear if Mexican-Americans will view more favorably the Cuban-American Rubio or Clinton, who has cultivated strong ties to that community in her more than 20 years in national politics.
Rubio would cast Clinton as old and the candidate of the past, the approach Obama took with McCain in 2008. But Clinton has some experience McCain did not have: heavy involvement in two successful presidential campaigns.