When Pita Limjaroenrat was a student at Harvard in 2008, he shadowed his American classmates who were campaigning at the time for Barack Obama. The experience gave him a window into electoral politics, from phone banks and polling data to knocking on doors and putting campaign flags on front lawns.

Fifteen years later, Pita said he used what he learned in Massachusetts to help his recent campaign in Thailand, where he stunned the country’s political establishment by leading his progressive Move Forward Party to a momentous victory.

For decades, Thai voters had known only two dominant political forces: one led by conservative royalists and militarists and the other by a populist billionaire living in exile. Supporters saw Pita, 42, as the candidate who represented change and a return to democracy after nine years of military rule that was preceded by a coup. On the stump, he promised to undo the military’s grip on Thai politics and revise a law that criminalizes criticism of the monarchy.