3) Tribal knowledge vs actual knowledge front: Yesterday, about half of all Republicans thought Obama was foreign born, and therefore an illegal occupant of the White House. How many Republicans will think the same thing one week from now? My guess is: about half. We've reached that stage on just about everything. It's probably been true of human beings throughout time, but is more obviously significant in politics now, that generally people don't act like scientific investigators, or judges in moot-court competitions, when parsing the logic and evidence behind competing arguments to come up with political views. They go on loyalty, and tradition, and hope, and fear, and self-interest, and generosity, and all the rest -- as the second half of my recent article on the new media discussed.

Here we have a wonderful real-world test: if "actual knowledge" mattered, the number of people who thought Obama was foreign-born would approach zero by next week -- with exceptions for illiterates, the mentally disabled, paranoid schizophrenics, etc. My guess is that the figures will barely change.

4) Back to the language front: Whether carefully calculated or off-the-cuff, Obama's use of the term "carnival barkers" at time 4:05 was perfect.

5) Speaking of carnival barkers: Every member of the political press knows that the chance of Donald Trump becoming the 45th President of the United States is zero. I say that the chance of Sarah Palin becoming president is extremely low but greater than zero. I will take any bet at any odds against Trump becoming president, for reasons I'll boil down to this: the same circumstances that would make Obama so vulnerable that a Trump could beat him (economic, political, military, or social chaos of any kind you want to imagine), would simultaneously motivate the Republican party to choose a "real" candidate with the best chance of winning the election and running the government. That is, if the Republicans think they have a serious chance to win, they're not going to blow that chance with Trump.

My real point is: knowing for sure that Trump's "lead" in the GOP polls now is a quaint artifact of name recognition, and knowing that there is no chance that his "colorful" background and prima donna manner could stand the long grueling, humiliating ordeal of the primaries and the caucuses and the endless interviews, how long will the press keep acting as the megaphone for this carnival barker? Why aren't they jumping all over him now, for the patent idiocy of his "birther" claim, rather than acting as if somehow he has scored a point by making Obama react? In reality, he'll be on the stage with the press' megaphone until people get bored with him -- which gradually but undeniably has happened to Palin.

6) Why didn't Obama do this before? Who knows. Perhaps some genius strategy to enmire the Republicans with the nuttiest part of their constituency? Perhaps a prideful sense that this kind of "prove it" gesture was beneath him? Perhaps resentment at the obvious racial component of the "not born here" sentiment? I don't know. But consistent with point #3 above, it probably wouldn't have made any difference.

This is not a great day for the press. For anybody, really -- but maybe a tie for worstness between Trump himself and those who have been barkers for his sideshow.

Back to "real" work. For more from The Atlantic, see Josh Green, Garance Franke-Ruta, Chris Good, and Adam Martin.

