WASHINGTON – After a tumultuous Election Night, Democrats on Wednesday morning had the big prize they desperately wanted: control of the House of Representatives. But Republicans could claim bragging rights as well by bolstering their hold on the Senate.

Before the 2020 presidential campaign begins in earnest, what have we learned?

Well, for starters, it's too late for that, because the next campaign is well underway. That's Lesson #1.

1. It's 2020 already

President Donald Trump filed for re-election the day he was inaugurated, and his campaign already has raised $100 million and begun airing TV and digital ads. So it should be no surprise that Trump campaigned more aggressively than any other modern president during the election midway through his term. He drew thousands of supporters to huge rallies, where he talked more about himself than the candidates he was there to boost. Some were in states crucial for his re-election prospects. On Monday, he closed the campaign with events in Ohio, Indiana and Missouri, and he officially announced his 2020 slogan: "Keep America Great."

For Democratic presidential hopefuls, the campaign was an opportunity to audition. A stream of potential contenders managed to make their way to Iowa, the state that is set to hold the opening presidential caucuses in 15 months or so: Senators Cory Booker of New Jersey, Kamala Harris of California and Bernie Sanders of Vermont. Plus governors Steve Bullock of Montana, John Hickenlooper of Colorado and Jay Inslee of Washington state. And Representatives Eric Swalwell of California and John Delaney of Maryland. Even Stormy Daniels' lawyer Michael Avenatti.

Some Democrats saw the midterms as a testing ground for a more assertively liberal message by the party's 2020 standard-bearer, whoever it turns out to be. "You showed the country that progressives can win and win decisively in the heartland," Democratic Sen. Sherrod Brown of Ohio, sometimes mentioned as a presidential possibility, told cheering supporters at his re-election victory party Tuesday night. "And you showed the country by putting people first and by honoring the dignity of work, we carry a state that Donald Trump won by almost double digits."

2. There's a new political divide.

A college diploma is the new political divide.

The gender gap – the tendency for women to vote more Democratic than men do – is familiar, a regular feature of American elections since 1980. Now a sharp divide over education has added another dimension and opened a new breach between white voters who have a college degree and those who don't. (African-American voters at all education levels typically vote Democratic, as do many Hispanics.)

A USA TODAY analysis of counties across the country who have the largest proportion of residents with college degrees showed a significant shift since the last midterm, in 2014. Then, they voted for the Republican congressional candidate by 15 percentage points. This time, they backed the Democrat by a single point.

The education gap is particularly yawning between college-educated white women and non-college educated white men.

Going into Tuesday's election, college-educated white women preferred Democratic congressional candidates by 18 percentage points, a Marist/NPR Poll found, while white men without a college degree backed Republicans by 33 points – a jaw-dropping 51-point gap.

That helps explain both parties' campaign strategies. Republicans focused on ousting Democratic senators from interior states like Indiana and North Dakota, where the population is whiter, older and less likely to have a college degree than states on the coasts. Democrats aimed their efforts at defeating House Republicans from suburban districts across the country where more residents have graduated from college.

This could signal the start of a realignment between the two major parties, with repercussions for presidential elections down the road. Consider this: 41 percent of white men without a college education strongly approved of Trump, one of his best showings. Among college-educated white women, 56 percent strongly disapproved, one of his worst.

3. Obamacare is recovering

In the past two midterms, no issue hurt Democratic congressional candidates more than the Affordable Care Act. Backlash to the law contributed to the historic loss of 63 House seats in 2010 – and with that Democratic control – and an additional 13 in 2014. Since Obamacare was enacted in 2009, Republicans campaigned on a promise to repeal it in four successive elections. Despite holding dozens of votes, they failed to do that even after winning the White House and control of Congress.

This time, in a turnaround, most of the ads that mentioned the Affordable Care Act this time were being aired by Democrats who accused Republicans of undermining its protection for patients with pre-existing health conditions. The Wesleyan Media Project calculated that close to 60 percent of the TV ads supporting Democratic congressional candidates last month mentioned health care; fewer than 10 percent of Democratic ads did in 2010 and 2014.

Republicans were on the defensive about their vote last year to weaken Obamacare's protections by allowing states to waive some of the law's requirements. What's more, Republican attorneys general in 20 states have joined in a lawsuit that challenges the constitutionality of the Affordable Care Act and would overturn the framework that protects coverage for those with chronic illnesses.

By the end of this campaign, Trump and other Republicans were promising not to repeal Obamacare but to preserve those protections, although they offer few specifics about how they would do that. In exit polls by a media consortium including ABC, CBS, CNN and NBC, four in 10 called health care the most important issue, far more than the number who cited immigration or the economy or gun policy.

4. Mega-money talks

Big money. Small money. More money.

Total spending on the elections topped $5.2 billion, the Center for Responsive Politics estimated – the biggest jump in midterm fundraising in at least two decades. Republican candidates raised record amounts of money, and Democratic candidates raised even more.

"There's more money in campaigns than you could have ever imagined," says Stuart Rothenberg, a veteran analyst with the non-partisan Inside Elections. "Who would think of spending $10 million in a House campaign?" This year, more than $46 million was spent in the most expensive House contest, in Georgia's 6th congressional district, and seven other House races saw total spending of more than $15 million.

The amounts surged both because of a handful of big donors – 13 contributors gave more than $10 million each – and millions of small ones. The huge Democratic war chest made it possible for the party to finance some longer-shot campaigns.

Rothenberg predicts there will be no turning back. "I don't think this is going to be a unique circumstance," he said. "It's a new reality."

5. Women roar

In the 2018 midterms, Trump defined the emerging Republican Party. Women – as candidates, contributors, voters and activists – defined the emerging Democratic Party.

That began the day after the president was inaugurated with massive women's marches promising resistance. What followed was two years of unprecedented activism. Take House races, tracked by Rutgers' Center for American Women and Politics: 476 women filed as candidates; the previous record was 298. On Election Day, 237 were on the ballot; the previous record was 167.

Records were broken by female contenders for every sort of office, for governorships, Senate seats and state legislative races. A record number of women donated to campaigns, the Center for Responsive Politics reported, and often to female candidates. Women contributed $159 million to female Democratic candidates, 2½ times the amount they gave two years ago.

"Women voters have outnumbered and outvoted men for nearly three decades, so that is not a new trend to this year, but what is notable this year is women's translation of advocacy and activism into both candidacy and political giving," said Kelly Dittmar, a political scientist at Rutgers and director of a project called Gender Watch 2018. "This year women are claiming their seats at the table."

6. Trump rules

A former Democrat who had never run for political office before his unlikely campaign two years ago is now the face of the Republican Party, redefining its tenets and reshaping its coalition.

The midterm elections underscored how completely Trump commands the GOP. Outsider Trump-like contenders upset establishment favorites for the gubernatorial nominations in Florida and Kansas. The senators most likely to criticize him, Bob Corker of Tennessee and Jeff Flake of Arizona, decided not to run again. The Republicans on the ballot who openly distanced themselves from the president could be counted on one hand, and not using all five fingers. One of the few GOP House incumbents who did, Carlos Curbelo of Florida, lost his bid for re-election.

The White House was quick to take credit for GOP gains in the Senate. "Frankly, the candidates who have embraced the president and the president has gone in to campaign for over the last several weeks are candidates that we see doing very well tonight," White House press secretary Sarah Sanders said in an interview on Fox News. "The president unified the party and brought it together."

Trump's primacy is unchallenged even though he publicly castigated such Republican allies as House Speaker Paul Ryan and privately alarmed top party officials with divisive rhetoric. Many urged him to focus on the strength of the economy; instead, the president's closing message trumpeted dire and unsubstantiated warnings about the threat from illegal immigration.

"What's surprising to me is how sustained and intensified the support is for Donald Trump," Lawrence Jacobs, director of the Center for the Study of Politics and Governance at the University of Minnesota, said when asked what he had learned during the midterms. "The much-predicted fall of Donald Trump as a candidate and as a political figure has not been the case among Republicans. If anything, he's picked up a more intense following."

Two-thirds of voters in the exit polls said the president affected their vote, about one in four to show their support for him, about four in 10 to show their opposition.

Trump – love him or loath him – defined the 2018 election. As he did in 2016. And as he surely will in 2020.