I've been thinking for a couple of days now about something Fox News anchor Brit Hume said recently: "Politics is about addition, not subtraction." No, I don't normally ponder the witticisms of Hume for days on end, and no, this wasn't an especially unique thing to say. But it did come at a time when the presumptive Republican nominee is trying to add to his coalition for the general election, while some of his fellow Republicans are screaming for ever more subtraction.

Whatever you think of Karl Rove, give him this: The man can see a demographic trend. He saw that Latinos were fast becoming one of the nation's critical demographic groups, and that something had to be done if the majority of Latinos were to become something other than permanent Democrats. And he actually succeeded in winning some Latino support for George W. Bush. But in 2006, as talk radio stoked a nativist strategy, Republicans gave up what inroads they had made into the Latino community. Ever since, a Mack truck has been heading the party's way. The Republican base is getting older, whiter and more conservative and now the party has alienated a growing segment of the country.

With that in mind, John McCain may have been the best possible candidate for the Republicans this fall. He hasn't been shy about reaching out to the Latino community, and supported so-called amnesty measures even as the rest of his party was screaming bloody murder. As the party's presumptive nominee, he has continued to try to reach out to Latinos. His campaign recently announced that he'll attend the La Raza Annual Convention in July, and it just released a Spanish-language Web ad, which can be viewed below.

But, of course, the nativists have no intention of going along with this quietly, and their anger may well torpedo Republican chances at winning over Latinos again. Michelle Malkin, for example, has been hyperventilating about McCain's appearance at the La Raza convention. This sort of thing may well be a preview of what's to come for McCain later this year.

Update: Just after posting this, I noticed a report that -- for the first time ever -- in Florida, there are now more Latinos who are registered Democrats than there are Latinos who are registered Republicans. Assuming that's part of the broader trend in the community and not just a reflection of the general shift to Democrats this year, that's really, really bad news for the Republican Party.