Donald Trump's flirtation with a presidential run in 2011 — circling the Republican field with rhetoric about Barack Obama's birth certificate, suggesting he might enter, generating enormous media coverage before ultimately declining — was treated by most political analysts as exactly what it appeared to be: a publicity exercise by a celebrity businessman who understood how to command attention.

The birth certificate claims — that Obama had not been born in the United States and was therefore constitutionally ineligible for the presidency — had been circulating in the political fringes since 2008 and had been thoroughly investigated and debunked. Obama's long-form birth certificate had been verified by Hawaiian state officials multiple times. The claim was false. Trump made it anyway, or rather made it loudly, as a vehicle for the kind of attention that substantive policy positions rarely generated.

The 2011 episode seemed to confirm a particular model of Trump: a media-savvy self-promoter who understood how to generate coverage without accountability, who had no particular policy depth or political organization, and who would ultimately calculate that the real estate of celebrity was more valuable than the uncertain gamble of actual political candidacy.

Most observers in 2011 who treated the question "is Donald Trump the next president?" as anything other than rhetorical were not taken seriously. The political science literature on what predicted presidential success — party infrastructure, donor networks, governing experience, polling breadth — gave Trump essentially no probability.

The 2016 election would require a significant revision of those models. But in 2011, the sensible answer to the question was no, and the reasoning behind that answer was not obviously wrong — it had simply underestimated variables that the 2016 cycle would make legible in retrospect.