As expected, Hillary Clinton’s big win in Puerto Rico has already become Exhibit A to demonstrate Barack Obama’s weakness among Latino voters. The Hillary campaign has flogged this hard in their efforts to convince superdelegates to reserve judgment on the primary until the convention in Denver. The argument itself ignores the diversity of elements within the “Latino” vote in the US and the fact that Puerto Rico doesn’t vote in the general election:

Ken Vogel reports that the Clinton campaign is using the results to openly argue that Barack Obama has a problem with Hispanic voters — an idea Clinton backers have previously mentioned only behind the scenes.

“It was a 100 percent Hispanic primary and it shows that he has a problem with the Latino community,” Terry McAuliffe, campaign chairman for Hillary Clinton, told a handful of reporters after polls closed Sunday. “He cannot close in this key core constituency,” McAuliffe added.

Voters in Puerto Rico are in some ways different from Hispanics living stateside, both because there’s a long tradition of racial mixing and because elections here tend to center around the debate over whether the island should remain a commonwealth or become a state or an independent nation. They also don’t vote in November.

Clinton has fared better than Obama with Hispanic voters in previous primaries. And her campaign has argued to superdelegates that she’d do better than Obama against presumptive GOP nominee in key states with large Hispanic populations.

I predicted that this would start being a big argument for Team Hillary, and they’re right on schedule. They don’t have much else to use now, and they are grasping at every straw still left to them. In one way, it’s an extension of the identity politics that have plagued the Democratic primaries all year. Hillary wants to stoke the competition between ethnic blocs within the Democratic coalition in order to destabilize Obama’s standing at the convention.

Will it work? Doubtful. Most Hispanic voters in the US would not look to Puerto Rico for guidance on their vote and have no connection to the US territory. Voters in Puerto Rico won’t matter in November. Florida, the state closest to Puerto Rico, will get influenced much more heavily by its Cuban expatriate community.

In the end, Puerto Rico will mean nothing in the march to the convention. If Obama really does have a Latino problem, its source lies elsewhere, as does its solution.