If you only get your political news from Twitter (spoiler alert: bad idea), you can be slightly forgiven if you bet your life's savings on the notion that progressive upstart Cynthia Nixon — former star of TV's "Sex and the City" — was going to oust New York's two-term governor Andrew Cuomo in a Democratic primary earlier this month.

This Nixon seemed like The One for capturing the supposed zeitgeist of 2018 — merging a Trumpian type of high-def celebrity with boldly left-wing or even socialist stances on a range of policy issues. And she faced the perfect foil in Cuomo — the heir to the rich Democratic legacy of his father Mario who many saw as the epitome of that party's decline: Ineffective (New York City's failing subways), corrupt (with a top aide convicted on a felony rap) and weak (cutting a deal with Republicans to save him from signing progressive laws that might hurt his presidential ambitions).

But in the end, nearly two out of every three New York primary voters went with the old-school Democrat, warts and all. Hundreds of thousands of voters in New York City's outer boroughs — heavily black or Latino, working class folks who are making ends meet and not spending 12 hours a day on Twitter — delivered Cuomo his 30-point margin.

Nixon's landslide defeat came as no surprise to a lifelong Democrat we'll call Mignon (her middle name) — a 48-year-old black woman who now lives in northern California but grew up in Buffalo and wrote a Twitter essay the morning after the primary about how her parents were two enthusiastic voters who supported the Democratic establishment and what a New York Daily News headline writer would call "Status Cuo-mo."

"Progress for my parents did not happen until a Democrat, and that was Lyndon Johnson" — who signed the 1965 Voting Rights Act that propelled dreams of African-American political empowerment, Mignon told me when I reached her this week by phone. She talked about her mom, who fled strife-torn Alabama in 1964 for a better life up North, and dad, a 74-year-old union steelworker — their loyalty to the Democratic Party, their political pragmatism, and their lack of use for "pie-in-the-sky ideas" of progressives like White House hopeful Sen. Bernie Sanders, who refuses to become a Democrat.

Mignon said her parents saw Andrew Cuomo as an heir to his popular late father Mario, New York's governor from 1983 to 1995. "Mario always had a plan," she said, adding that her parents "like plans, incremental steps." And she added that — unlike young left-wing voters flocking to Sanders or future congresswoman Alexandria Ocasio-Cortez — voters like her parents are not ashamed to consider themselves capitalists.

There is a huge disconnect within the Democratic Party right now — a rift that was critical to 2016's shock election of President Trump. The re-emergence of the one modern Democrat who could glue many of these broken pieces together — Barack Obama, who brings his energetic push for the party's 2018 candidates to Philadelphia on Friday — and a looming midterm election in which anger over an autocratic president can be channeled into state and local races are likely to paper over this Democratic family feud … for now.

But when voters wake up on November 7, they'll hear the gong to start the sure-to-be-insane national election of 2020, with as many as 20 or more candidates from delusional billionaires to congressmen you've never heard of prepared to yank hard on every gaping fault line within the party of Andrew Jackson, FDR and JFK. Those cleavages could give Trump a second term in much the same unlikely way that he won his first one. And yet when you put your ear to the ground and listen to the Democratic rumblings, the various sides still don't understand each other, or even know how to talk to each other without yelling.

Here's a quick field guide to the three Democrats you meet on Twitter, or in the voting booth … or sitting on their couch when they should be voting:

The Bernie Sanders Democrat

U.S. Sen. Bernie Sanders (I-Vt.) speaks at the Center for American Progress’ Ideas Conference in May.
RON SACHS / CNP
U.S. Sen. Bernie Sanders (I-Vt.) speaks at the Center for American Progress’ Ideas Conference in May.

The Bernie Sanders Democrat very often doesn't even call himself or herself a Democrat, preferring terms like progressive or democratic socialist or, increasingly, registering as an independent, as Sanders himself does. Although you find them everywhere, this species of left-of-center voter predominates among the under-30 electorate, in cities and especially in gentrifying neighborhoods; it tends to be somewhat more male than female. Animated by the holy trinity of Medicare-for-all, free college and the $15 minimum wage, they are leftists who may engage in Democratic politics but spend most of their time complaining about Democrats, or at least Democratic elites, as too tied to big corporations and big donors and too happy to bend over for Wall Street.

The Hillary Clinton Democrat

Hillary Clinton is greeted with a sea of flags on the fourth night of the DNC in Philadelphia July 28, 2016.
CLEM MURRAY / Staff
Hillary Clinton is greeted with a sea of flags on the fourth night of the DNC in Philadelphia July 28, 2016.

The Hillary Clinton Democrat, a cohort that is overwhelmingly female, tending to be white, suburban, and middle or even upper-middle-class, often with a college degree. Some of them even voted Republican back in the 1980s or '90s for the low taxes — but started drifting away after Anita Hill in 1991 or as they saw the GOP get more Southern and then more crazy. These voters felt existential shock and despair when they saw America (technically, the Electoral College) reject a qualified woman — whose life struggles mirrored their own — in favor of a man whose non-stop lying and admission of sexual assault was now their worst nightmare in the Oval Office. Their profound sense that the world has betrayed them has made them the backbone of the so-called Trump Resistance.

The John Lewis Democrat

U.S. Rep. John Lewis stands in front of John Lewis Freedom Parkway moments after its new name was unveiled in Atlanta, Wednesday, Aug. 22, 2018. Atlanta is honoring Lewis by renaming a street after the civil rights icon.
BRINLEY HINEMAN / AP Photographer
U.S. Rep. John Lewis stands in front of John Lewis Freedom Parkway moments after its new name was unveiled in Atlanta, Wednesday, Aug. 22, 2018. Atlanta is honoring Lewis by renaming a street after the civil rights icon.

The John Lewis Democrat, in honor of the 1960s civil-rights icon still in Congress, although you could also call them Andrew Cuomo Democrats or Dianne Feinstein Democrats, since their votes tend to keep these establishment figures in power, despite the derision from the far left. Tending to be older and often (but not exclusively) non-white, this group reflects the growing conventional wisdom that the real base of the Democratic Party is older, church-going African-American women. These are the Democrats who — quite unlike the Bernie Sanders crowd — are proud to identify as Democrats, having grown up revering tales of FDR or JFK. They tend to prefer politicians who can cut deals and win resources for their communities over those with lofty but impractical ideas. And they cherish their right to vote and show up at the polls religiously, which is what gives them such outsized influence.

There's many caveats. Millions of Democrats don't easily fit these boxes (and I'll probably get angry emails from every one). These groups can also overlap and often their interests align, as when the majority of the John Lewis Democrats supported Clinton in 2016 and joined those suburban women in delivering her the nomination. But often they're figuratively at each other's throats. A lot of Hillary and John Lewis Democrats are still furious at Sanders and his supporters, insisting their apathy in the fall of 2016 put Trump in the White House. The Berniecrats still think establishment Dems are addicted to Wall Street money. Post-Trump, some core Democrats have looked at the suburban "resistance" with a jaundiced eye, wondering why these women weren't "woke" to America's flaws before 11/8/16.

These fissures help explain why Obama is such a significant figure — both in 2008 and again today, as he reappears in Philadelphia and elsewhere seeking to whip up enthusiasm and bring some unity ahead of November. It's easy to forget that back in 2007, Obama was basically the candidate of the far-left dreamers, including many who'd migrate to Sanders eight years later, while Hillary Clinton started out with substantial black support among voters who'd adored her husband. (Indeed, John Lewis himself endorsed Hillary at first, then switched.) When white voters delivered the Iowa caucus to Obama, many African-Americans realized that Obama could be the fulfillment of LBJ's 1965 Voting Rights Act. That's how Obama bridged the deepest divides among the Democrats, and it's hard to see who will repeat that.

The other night, MSNBC's Chris Hayes hosted a "town hall" event in Flint, Michigan that spotlighted four young voters who didn't show up or went third-party on Election Day 2016. These voters insisted that they weren't apathetic but that between Clinton and Trump they just "couldn't vote for the lesser of two evils." With his approval rating drifting below 40 percent, Trump's 2020 re-election strategy hinges less on turning out his right-wing base and a lot more on increasing the number of these discouraged voters, to persuade them their vote won't make a damn difference.

The Democrats' best hope of countering that is probably the rise of a figure who can do the unlikely thing that Obama did in 2008, and somehow find the right mix of policy and biography to unite factions of the party that two long years after the Trump debacle still seem much more focused on what divides them. Somewhere — maybe in the current quasi-candidates, maybe not — is a leader brimming with new ideas that will excite the Berniecrats, yet able to convince the party's faithful, like those black women in Queens who just turned out for Andrew Cuomo, that she or he is the rightful heir to FDR, JFK, LBJ … and Obama. Especially Obama.

If that candidate doesn't come out to see the shadows of Democratic greatness, the forecast calls for six more years of Trumpian winter.