Donald Trump has now wasted three news cycles to proffer his theories about President Obama’s birth certificate. Tim Pawlenty has issued a definitive statement: “I think President Obama was born in the United States.” Jerome Corsi, who can append “#1 New York Times best-selling author” to his name thanks to his “swift boat” quickie in 2004, is already promoting Where’s the Birth Certificate?

Why won’t birtherism go away? The standard answer is this: because Barack Obama won’t release proof of his citizenship. Sorry, no dice: He did release proof of his citizenship, in June 2008—and it helped birtherism go mainstream.

There were attempts to prove, via the work of amateurs with pen names, that the Certificate of Live Birth that Team Obama had put online was a forgery worthy of MI-6 or Clifford Irving. There were complicated legal theories about how Obama couldn’t be a citizen even if he was midwifed by Betsy Ross, because his deadbeat dad had saddled the future president with British citizenship. And most of this happened before Obama was sworn in, when a stupid person could hope that the Supreme Court would nix the inauguration.

So why won’t birtherism go away? After all, lots of crackpot movements and theories go away. The all-wars-are-for-oil side of the left-wing anti-war movement shrunk to fit a pencil case after Obama was elected. Glenn Beck’s ratings surged high enough to get him two unofficial biographies and the covers of Time and Fortune, and now they’re sagging so low that Fox News is hinting it may drop him. Once some obsession or movement either wins or loses all hope of winning, its adherents find other things to do.

But birtherism is with us, now more than ever. It used to be odd and unprofessional to ask a politician whether he had any doubts about the president’s American birth. It was in the “kook question” category. There’s theoretically nothing stopping a reporter from raising her hand at a press conference and asking a presidential candidate whether, say, he thinks the Bilderberg Group engineered the financial crisis so its members could buy up foreclosed homes and turn them into meth labs. A question about Obama’s birth certificate used to be in that same category. Now it isn’t.

Is this unfair? Trump—whose campaign may qualify as a massive, “I’m Still Here” publicity stunt—is responsible for the sudden acceptability of the question. On The View, he reminded viewers that he went to “the best schools,” so he knew that documents are forged all the time, and he didn’t trust what he’d heard about Obama. Even after Tuesday, when he finally released a scan of his 1946 birth certificate to ABC News, that claim hung in the air. It echoed what some birthers still say; it gave them wider uncritical media exposure than they’d gotten since Lou Dobbs left CNN.

One reason Trump has been able to do this is that two schools of birtherism have developed since 2008, and one of them has become a surprisingly comfortable place for conservatives to lounge. There have always been Orthodox Birthers. They start with the belief that Obama cannot be eligible for the presidency. They trust evidence they find online—an erroneous report about “Obama’s grandmother” saying he was born in Kenya, for example—which stays online forever, just like amateur diagnostic reports of how crashing planes couldn’t possibly have brought down the Twin Towers. If that evidence is challenged, they look to theories about what the founders thought “natural born citizenship” meant. Phil Berg, the attorney who filed the first birther lawsuits and who held a “March on Washington” in 2010, says Obama lost his citizenship because a school form from Indonesia calls him Indonesian. Another theory says Obama can’t be president because his father was Kenyan and that made his son a British citizen by default. (This theory would disqualify Trump, whose mother was Scottish.)

What Trump is embracing, and Corsi is selling, is Reform Birtherism. It’s deductive. “There’s something on that birth certificate that he doesn’t like,” said Trump last week. “I don’t know what is on the document,” said Corsi in 2009. The truth is unknowable, because Obama is hiding something about his birth documents.

This is all obtuse, because unless the state of Hawaii has issued a false document and the Honolulu Advertiser and other media were defrauded when they printed Obama’s 1961 birth announcement, there’s more proof of his origins than there is proof of most things. If the president lost his original paper certificate at some point, he’s in the same boat as Greta Van Susteren, who confessed as much in an interview with Trump.

So why bring this up? If Trump is actually running for president, he’s doing it because polling indicates that at least 27 percent of Republicans have doubts about Obama’s origins. There are probably going to be more Republicans primary voters who have these doubts than think abortion should be illegal. So being a Reform Birther is saying you’re in solidarity with state legislators who are demanding birth certificates from the next presidential candidates.

This is pretty pathetic, even for a presidential campaign. Those legislators, and the voters they’re pandering to, don’t really know what they’re talking about. Mae Beavers, a Tennessee state senator, has introduced a bill that would require a “long-form birth certificate” from 2012 candidates. She appeared on a radio show to discuss it and was asked what a “long-form birth certificate” was. She didn’t know; she had just modeled the bill after what other states had done.

What does someone like Pawlenty have to gain when he dismisses all of this? Quite a lot, actually. Millions of Republicans may doubt Obama’s citizenship—but millions more don’t, or don’t care. Many of the Republicans who do have doubts don’t actually know or think that Obama should be kicked out of office on a technicality.

The Republicans who can shape elite opinion—this does not include Corsi—hate even thinking about this. If an investigation proved that Obama had gotten into Columbia and Harvard Law with mediocre grades, he might only win as many presidential elections as George W. Bush. Lots of Republicans think that birtherism is a good way for the White House to make their party look crazy.

With his definitive statement, Pawlenty appeals to those Republicans. He appeals to the political media, too. He’s jumped one of the lowest bars in politics—but he’s jumped it, and some other Republicans still haven’t, or won’t. Pawlenty wins a stamp of approval—not crazy!—that’s incredibly easy to earn. Soon some other candidates will go for that stamp. They have a lot of time. The birthers aren’t going anywhere.