The former secretary of State has been telegraphing his unease with Romney's foreign policy for months.

President Obama scored a big endorsement Thursday morning from Colin Powell, the former chairman of the Joint Chiefs of Staff and Bush Administration secretary of State. "I think, generally, we've come out of the dive and we're starting to gain altitude," Powell said on CBS's This Morning. "I voted for him in 2008, and I plan to stick with him in 2012. I'll be voting for he and for Vice President Joe Biden next month."

There's no reason to expect Powell's endorsement will have a major effect on the election: it's a tight contest; the margin will likely be close no matter what; Powell's profile is lower than it once was; and few voters will be swayed by foreign-policy arguments. But Powell is a self-described lifelong Republican and was one of the "Obama Republicans" who notably defected from the GOP in 2008. He's also one of the few to again back the president publicly.

That party affiliation has brought out some ugly reactions, most notably from Ben Shapiro of Breitbart.com. This will be no surprise to those who remember Shapiro and Breitbart.com's hyping of a video of Obama embracing controversial Professor Derrick Bell two decades ago. Here's a screengrab from Shapiro's Twitter feed this morning:

It's certainly plausible that both Obama and Powell have benefited from affirmative action, although it's also apparent that both men -- regardless of political views -- are talented and could not have achieved what they have only based on racial considerations. Moreover, this is a great example of a phenomenon that Conor Friedersdorf has noted: "Anyone with open eyes can see that people on the left and right illegitimately exploit racial divisions in bids for power; that many conservatives are as race-obsessed as any liberal; and that today's conservative movement needlessly brings up race all the time." *

Here, Shapiro can see no plausible reason why Powell would back Obama other than the color of their skin. But of course Powell has been telegraphing his worries about Mitt Romney's campaign for months, even as he held back on endorsing either candidate. Powell famously battled with neoconservative foreign-policy voices in the Bush Administration, including John Bolton, Donald Rumsfeld, and Dick Cheney. In May, he went on Morning Joe to express his deep concerns about the number of neocons in Romney's circle, noting in particular the Republican nominee's claim that Russia was America's greatest geopolitical foe.

"Come on, Mitt, think. That isn't the case," Powell said then. "I don't know who all of his advisers are, but I've seen some of the names and some of them are quite far to the right. And sometimes they might be in a position to make judgments or recommendations to the candidate that should get a second thought."

Since then, Romney has mostly stuck with a hard line on foreign policy, although he struck a more dovish tone in Monday's debate on foreign affairs. And he has very visibly stumbled on foreign policy, from a gaffe-marred trip to Europe and Israel to his widely panned initial reaction to incidents in Cairo and Benghazi on September 11 that left four Americans dead. If Powell was nervous about Romney's overseas abilities in May, there's no reason he'd be more assured now, and no reason why he'd opt for the Republican over Obama.

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* An instructive counterexample came yesterday, when a minor brouhaha broke out over Sarah Palin accusing President Obama of a "shuck and jive" over Benghazi. While the phrase tends to have racial overtones, it's easy to imagine that Palin -- who famously seemed to be unaware of the meaning of "blood libel" -- might mangle a phrase. Shapiro, as we'll see, leaves no room for such doubt.