With Donald Trump’s inauguration on Friday—a thing that still sounds batshit crazy—there’s a lot of remembrance in the air about the last eight years. To summarize: We elected the first black president, recovered from the biggest banking crisis in American history and the worst economic downturn since the Great Depression, achieved nearly universal healthcare and then elected a reality TV star with no previous political or military experience to be the next president.

How did it happen? Is it all connected? Are we just digital bits in some 400-pound New Jersey kid’s video game, as Trump (sort of) foretold? I have no guidance to offer on that last question, but the Frontline documentary series tackles the others in three new episodes—the two-part Divided States of America and Trump’s Road to the White House—beginning last night on PBS with part one of Divided States, a look at President Obama’s tumultuous, historic first term, with particular attention to sharp partisan differences that mutated and grew over time.

Divided States identifies John McCain’s naming of Sarah Palin to his ticket in 2008 as a major catalyst in the rise of a populist movement within the Republican Party. “That was really the first time you had this establishment vs. grassroots conflict,” Republican consultant Frank Luntz says, “and you had it because, for some people, Sarah Palin was Margaret Thatcher.” If that strikes you as patently ridiculous, you’re not who Luntz is talking about.

Couple that with a toxic antipathy on the right for Barack Obama. Divided States includes footage of people calling Obama a Muslim and a terrorist as they walk into a McCain campaign rally, and McCain himself at a town hall correcting a woman who calls Obama an Arab. When McCain says Obama is “a decent person,” the crowd gasp as though he had just insulted them.

In the fall of 2008, when Lehman Brothers fell and the U.S. banking system teetered on collapse, one Republican after another came to the House floor to rebuke President George W. Bush and their own leadership for asking them to approve a $700 billion bank bailout. When John McCain says that “it’s time for both parties to come together to solve this problem,” he’s talking about his party. The bailout failed in the House—at least on the first try—and made clear that the Republican Party was deeply divided between establishment and anti-establishment factions. When it passed four days later, Democrats provided most of the votes.

That coalition evaporated with Barack Obama’s election. On the evening of his inauguration, House and Senate Republicans were at a steakhouse plotting, as Mitch McConnell would later openly declare, to do everything they could to make Obama a one-term president. The strategy was simple: Oppose everything. This is not a partisan observation; many of those in attendance have admitted as much, and two—Newt Gingrich and Frank Luntz—discuss it openly in Divided States.

When Obama met with House Republicans only days later to discuss what should be included in an economic package, former Rep. Eric Cantor quotes him as saying, “Elections have consequences and I won, so we’re gonna do it my way.” The verbiage sounds dubious, but Obama unquestionably had a strong mandate to fix the economy and big Democratic majorities in Congress to pass an ambitious recovery plan. (Cantor presenting himself as a good-faith negotiating partner is more than a little disingenuous, given the “oppose everything” meeting only days earlier.) When Congress passed the $787 billion Recovery Act, more than one third of which was in the form of Republican-friendly tax cuts, only three Republicans in the Senate and not a single one in the House voted for it.

A week into Obama’s presidency, the same Republicans Party that had been openly divided a few months before was now united in opposition, and an anti-bank, anti-Washington, anti-Obama backlash was coming from the right with the Tea Party and from the left with Occupy Wall Street. With the next major legislative effort—healthcare reform—congressional Republicans, right-wing talk radio and business lobbies framed a worst-case scenarios of death panels and black helicopters and spread it through the grassroots. Obama won again, but the margin was narrower and the legislative chess more involved.

Frontline has been making political-affairs documentaries for 35 years and has enough gravitas in Washington to get broad cooperation for these big-picture assessments. The roster of senior Obama aides, congressional leadership, political observers and respected journalists interviewed for Divided States is impressive, and those individuals are speaking at just enough of a remove to be fairly candid while remembering the details.

The last eight years have been extraordinarily eventful, and much of what transpired, from the passage of the Affordable Care Act to the election of Donald Trump, defied the conventional wisdom of the time. We’ll learn a lot over the next decade about how economic, business, technological, social and political forces combined to get us where we are, but Divided States is a good start on the political.

The broad strokes of the Great Recession and President Obama’s first term is not a new story and doesn’t fully explain how the country changed during those years or how we got to the bizarre current state of affairs, but few can deny it’s a weird, messy, fascinating story that bears repeating.

Part two of Frontline: Divided States of America airs tonight at 9 p.m. ET/PT on PBS and will be available later this week at PBS.org and on the PBS streaming app.