A year after President Joe Biden's inauguration, more than two-thirds of Republican voters believe his election was illegitimate. The idea that the 2020 election was stolen from Donald Trump is now a defining issue of the Republican Party. Yet the story of how lies about election fraud made their way to the center of American politics has not been entirely told. 

In a new investigative collaboration, FRONTLINE and ProPublica trace the hidden sources of disinformation about the 2020 election, demonstrating how a handful of people have had an outsized impact on the current U.S. crisis of democratic legitimacy.

FRONTLINE examines the fossil fuel industry's history of casting doubt and delaying action on climate change. This three-part series traces decades of missed opportunities and the ongoing attempts to hold Big Oil to account. Part Two: Doubt explores the industry's efforts to stall climate policy, even as evidence about climate change grew more certain in the new millennium.