A deep look into the growing divide in America from the Barack Obama era through the presidency of Donald Trump.

Frontline: America's Great Divide

Part of a series of portraits of past first ladies, this PBS documentary explores the political and personal lives of former first lady Nancy Reagan, who moved from Hollywood to the California governor's mansion -- and eventually the White House. While playing a behind-the-scenes but integral role in the president's policies, she also launched a campaign to "Just Say No" and later cared for her ailing husband as he suffered from Alzheimer's.