That was then. It ain't now.
A legitimate question for Marco Rubio: All right, you're running for president.
Who's your base?
[T]he senator’s attempts to win over both the conservative base and more left-leaning minorities have mainly served to alienate, one by one, the very groups he would need to win the presidency.
Immigration reform being the prime example there, with the tea party now convinced he is a traitor because he thought immigration reform might be a good idea and Latino groups just as angry with him for abandoning the idea after he started being pilloried by, well, racists. Think Progress also points out that the business community isn't pleased with his vows to fight against normalized Cuba relations, since they stand to make a lot of money from lifting the Cuba embargo, and that he's not particularly trusted by religious voters (publicly condemning the pope for not supporting "freedom" is, helpful hint, not going to woo many voters you'd want to be publicly seen with.)
On the other hand, he's a dedicated hardliner on most issues of the day. He's a military interventionist who supported the Iraq War even long after most others had given up the ghost on that one. He's against even basic LGBT rights. He's not just against raising the minimum wage, he's against having a minimum wage at all. He's against net neutrality for frankly baffling reasons that can only be parsed out as him not understanding what it is.
So he's every other Republican, but one that has isolated much of his base and yet considers himself "uniquely qualified" to lead the nation based on heck-if-anyone-knows. If there's reason for optimism on the Rubio team, it might be a new poll that suggests the wider pool of Republican primary voters are indeed still courtable, and that his past policy gaffes and flip-flops are therefore recoverable if he stops doing them before the primaries get underway in earnest. Good luck with that.
I don't think Marco Rubio currently has a true base to speak of, but he could build one. He's more polished (water incident aside) than many of the other presidential dreamers, and can certainly make a stronger case for himself than Rand Paul or Ted Cruz. It will be interesting to see whether he can differentiate himself from those other candidates. Also interesting: Of the three Republican candidates that have officially announced (Paul, Cruz, Rubio), all are Republicans who have caused big headaches for their party. Cruz for the shutdown, etc., Paul for being Paul, and Rubio for leading the party into a supposed enlightenment on immigration policy that backfired terribly and propelled the xenophobes of the party into uncontested stewardship of that policy. Three cases of failing upwards?