There’s a simple reason why the Republicans will probably put Florida Senator Marco Rubio on their ticket as the vice-presidential candidate. It’s not because he’s well-qualified, because he isn’t, or that he’s got a record of moral probity, because he doesn’t. He’s a good-looking guy, which doesn’t hurt, and he’s from Florida, which would definitely help. But the reason that he’ll most likely be on the ticket is because of demographic changes to the country that make it almost impossible for the Republicans to win if Obama repeats his performance of 2008 in winning two-thirds of the Latino vote. Not only will the Latino share of the electorate have grown substantially in the four years between the two elections, but the Republicans have traded in the Latino-friendly attitude of the Bush administration for the strident anti-Latino attitude of Arizona Governor Jan Brewer. There is basically zero chance that the Republicans will improve their standing with Latinos over where it stood in 2008. And that’s where things get interesting. National Journal’s Ron Brownstein did some calculations based on past election data and information recently released by the Census Bureau. Assuming that Obama gets the same percentage of minority vote in 2012 that he got in 2008, he found the following:

Obama, for instance, won Florida last time with 42 percent of the white vote; under this scenario, if he maintains his minority support he could win the Sunshine State with just under 40 percent of the white vote. With equal minority support in Nevada, the president could win with only 35 percent of the white vote, down from the 45 percent he garnered in 2008. Likewise, under these conditions, Obama could take Virginia with just 33.5 percent of whites, well down from the 39 percent he captured last time. In New Jersey, his winning number among whites would fall to just over 41 percent (compared with the 52 percent he won in 2008). In Pennsylvania, under these circumstances, 41 percent of white votes would be enough to put the state in Obama’s column, down from the 48 percent he won in 2008.

Several senior Democratic strategists believe that the demographic trends may allow them to expand their target list in 2012. Top analysts on Obama’s team are intrigued by Georgia (where the minority share of the adult population has spiked to 41 percent) and Arizona (where it has nearly hit 37 percent).

The Census data showed a more accelerated browning of America than experts anticipated, which means the Republicans got a nasty surprise. They know they have to drag down Obama’s numbers with whites in order to compensate for the smaller percentage of the electorate that is white. But they may have miscalculated how short their window is for winning elections as the White Persons Party. It can still work in a low turnout midterm where the president is not on the ballot and the economy is in the crapper, but there’s no future in it. Yet, when you see people talking about Obama’s birth certificate and his religious faith and making all kinds of crazy-ass racist statements, now you know why they’re doing it. They can’t let the president get more than 40% of the white vote or they’re finished.

If they can hold him down, though, and peel off a part of the Latino vote by nominating the only elected Republican Latino who has even a remote claim to being a plausible president, they might just beat demographic reality one more time before the window on White Power-campaigning closes forever.