The choice could have some appeal. The Florida Senator is a tea party sensation. He is also, yes, Hispanic which could be tempting for the GOP. After all, he could be a way for them to kill two birds with one stone.
Get the tea party someone they can be enthusiastic about-as they are less excited about Romney-and also at the same time get them in with Hispanics who they currently trail very badly with-recent polls have shown Obama's advantage with them as large as 70-14; and a 20 point lead with women to boot.
Of course this is not a fool proof strategy-far from. The GOP has tried this move before and it often doesn't work. In 2008 the nomination of the first female vice presidential candidate didn't save McCain's campaign.
One nasty thing Republicans sometimes say about blacks is that they will vote for anyone if he's black-or that their support for Obama is wholly based on race.
Yet their own history shows this is not so-African-Americans have shown they will not vote say for a black conservative, black or no. There's no reason to assume that Hispanics will totally look past the GOP's sorry record over the last 4 years with all these Republican states passing all these anti-Hispanic draconian laws and vote for someone who is in fact ultra conservative, simply because he is Hispanic.
Indeed, another failed gambit is the social conservative route. It's true that as a group black Americans are more conservative than other Americans-this is somewhat true of Hispanics as well. In the Black community, things like gay marriage are still very controversial-for an example of this try perusing The Black Agenda Report sometime.
Still GOP attempts to get Blacks to vote their prejudices against their own interests doesn't work. So Rubio is hardly a magic bullet. However, it may seem intriguing enough for a party with long odds with as unpopular candidate as Mitt Romney who completely lacks sex appeal.