Two things stood out to me about Obama's speech (in Independence, MO no less) about patriotism today, one on strategy, one on patriotism itself.
The strategy is a smart one, and indicative of a candidate in a commanding position. Obama knows full well what awaits him this Fall - attacks (disguised or otherwise) on his race, faith, patriotism. Rather than wait for it, he is attempting now to preempt their potency when they do inevitably come. (He has already done the same as regards race and faith.) Someone in a weaker position would have waited in vain in the hope that the inevitable would not come. Obama dares address patriotism because he believes he can handle the charge that he lacks it.
Let's talk content - of patriotism, specifically. Obama wrapped his speech in Americana - the revolution, the Declaration, Jefferson, Lincoln, Franklin Roosevelt, Mark Twain, astronauts, soldiers, the flag - even as he was saying something rather subtle about the relationship between patriotism and dissent. While the metamessage of Americana was necessary to diffuse the potential fallout from his comments about dissent, the perceived necessity for it suggests that perhaps the message was the metamessage. This rhetorical concession reveals something rather profound about patriotic sentiment that Democrats have yet learned to lucidly articulate (the key word being "articulate," as opposed to loosely imply via a list of Americana): that there is an uneasy and complex relationship between love of country and disagreement with government. History tells us, at least as far back as the experience of the anti-Federalists suggest, that victory trends toward those who choose not to wrestle with this complex relationship and to accept the prima facie inconsistency between patriotism and dissent. Obama's inadvertent rhetorical dressing (as is the fact that he has put his flag pin back on) conceded as much.