The first thing you should know about "birtherism" is that it should have died years ago. In June 2008, shortly after locking up the Democratic presidential nomination, Obama's campaign released a Certificate of Live Birth from the state of Hawaii. No presidential candidate had ever made a move like that.
But the fever swamp was not drained. That 2008 document dump inspired exciting new fantasies. Why did the campaign release a "short form" certificate, instead of a "long form" one? What was up with the typesetting? Since Obama's father was born in Kenya, was the Democratic nominee a de facto citizen of the Commonwealth?
I covered all of these rumours as a reporter for the libertarian Reason magazine. They were easy to disprove. Often, it seemed that I was the only journalist who called the source of an Obama rumour, or the litigator behind an Obama lawsuit, and asked them for their facts.
The stories fell apart like day-old bread. For example, a full listen to a tape that had been cited as an Obama relative revealing that she'd witnessed his birth in Kenya turned out to be a tape of a desperate birther calling the relative's house and being told again and again that she'd witnessed no such thing.
The stories were so obviously bogus that I expected them to fade after Obama took office. They didn't fade. And I should have predicted that. Why? Because my reports on the bogus stuff were popular among two types of readers. Liberals liked to hear about this stuff because it made conservatives sound crazy. And conspiracy theorists, who have never given up on anything merely because the facts didn't will out, liked the attention they were getting.
American politics are only rarely about substance. They are far more often about what you can say to gee up your base, what drives the other team crazy, and what gets the media to pay attention to you. This is a toxic brew, and there's plenty of it left to drink.
David Weigel is a contributing editor at 'Reason' and political reporter for 'Slate'