WASHINGTON — A few hours into election night 2018, it felt like it was happening again — Donald Trump and the GOP were about to defy political gravity.

Republicans were ahead in Florida’s gubernatorial and Senate contests (and it would stay that way); Stacey Abrams was losing in Georgia; the GOP was cruising to victory in Indiana’s Senate race; and Republicans took the first marquee House bellwether of the night in KY-6.

But by 11:00 p.m. ET — and especially in three weeks since the midterm elections, as races have been called and more votes have come in — it was clear that political gravity caught up to Trump. And that might have been one of the more consequential outcomes of the 2018 midterms:

that being a president with a 45 percent job rating (or lower) will hurt your party, like it did to Bill Clinton in 1994, George W. Bush in 2006 and Barack Obama in 2010;

that focusing ONLY on your base can’t save your party from losing up to 40 House seats and control of Congress, even when the unemployment rate stands at 3.7 percent;

and that the most favorable Senate map in generations couldn’t net the GOP more than two net pickups.

To be sure, Trump and Republicans turned out their voters, ensuring that the GOP didn’t lose more House seats and control of the U.S. Senate. They won key Senate and gubernatorial contests in Florida, Iowa and Ohio — all important presidential battleground states. And they crushed Democrats in rural America, as the The New York Times’ Jonathan Martin wrote over the weekend.

But that the laws of political gravity applied to Trump in 2018 — and we also saw this play out in Virginia’s gubernatorial race in 2017, in Alabama’s Senate contest in December 2017 and the special PA-18 race in 2018 — provide an important lesson for 2020: Political fundamentals still matter.

Looking ahead to 2020, can Trump broaden his popularity and raise his job rating? And can he do so if the U.S. economy is no longer firing on all cylinders? Those might be two of the most important questions to answer over the next two years.

And remember this: The political fundamentals always pointed to a close election in 2016, especially after the Democrats had been in charge of the White House for eight years. (A party holding on to the White House for more than two terms has happened only once since FDR and Truman.) Much of the political world, however, discounted that political reality in 2016.

So where’s the pivot for the president?

Here’s another important reminder: Suffering midterm losses doesn’t hurt your re-election chances. After all, Clinton and Obama went on to win second terms after humbling midterm defeats.

But as one of us pointed out on “Meet the Press” yesterday, those presidents acknowledged their humbling defeats — and they changed course.

“When President Clinton lost control of both houses of Congress in 1994, the day after the election, he accepted his share of responsibility. Mr. Clinton then worked with the new Republican majority on issues like welfare reform and balancing the budget. And two years later, both were easily reelected, the Republican Congress, and President Clinton.

When President Obama lost the House in 2010, he called the 63-seat defeat a shellacking. Mr. Obama then worked with Republicans to [extend] the Bush tax cuts … something he had opposed as a candidate. And two years later, he and that Republican Congress, were easily re-elected.”

A stark contrast: The day after the election vs. 3 weeks later

By the way, we can’t emphasize enough how DIFFERENT the 2018 midterms look three weeks after Election Day — compared with the day after. Consider:

The day after: We knew Democrats had won the House, but the gains — at the time — appeared to be in the low 30s, with nearly a dozen races still to call.

Three weeks later: Assuming Dems win in UT-4, they’ll be at +39. And they *could* hit +40 if they pull off winning CA-21.

The day after: Democrats were leading in the popular House vote by 5.8 points, 51.9 percent to 46.1 percent. That’s a nice gain, but not the R+7 we saw in 1994, the D+6.4 from 2006 or the R+6.6 from 2010.

Three weeks later: According to the Cook Political Report’s David Wasserman, the Dem popular vote advantage is now a full 8 points, 53.1 percent to 45.1 percent.

Indeed, Dems are getting close to 60 million votes. In 2008, John McCain got 60 million votes; Mitt Romney got 61 million in 2012; and Trump got 63 million in 2016. It’s stunning that Dems got as many House votes as the GOP presidential nominees in 2008/2012/2016.

The day after: Dems looked like they could be on the verge of losing the Senate races in AZ-SEN and MT-SEN, as well as FL-SEN, putting them at -4 for the Senate.

Three weeks later: Dems won MT-SEN and AZ-SEN, but lost FL-SEN in a recount, putting them at -2.

Trump heads to Mississippi to campaign for Cindy Hyde-Smith

Three weeks after Election Day 2018 also marks Mississippi’s Senate runoff between Sen. Cindy Hyde-Smith, R-Miss., and Democrat Mike Espy, which takes place tomorrow.

And Trump campaigns for Hyde-Smith tonight at 8:00 p.m. ET.

Politico: “Republicans think Cindy Hyde-Smith will ultimately pull out a win in Mississippi's special Senate election on Tuesday. But they say the race has tightened — and after what happened in Alabama last year, they're on edge. A swirl of controversy surrounding the Republican senator — stirred up by her comment about attending a ‘public hanging’ — has given Democrat Mike Espy momentum in the home stretch, officials from both parties say. Hyde-Smith has never trailed in polling, and Democrats acknowledge she's likely to win, but they argue that her flubs have given Espy a very narrow opening if everything breaks his way.”

The uncalled House races (one)

UT-4 (Democrat Ben McAdams is ahead of Republican Mia Love, 50.1 percent to 49.9 percent)

— GA-7 (NBC declared Republican Rob Woodall the apparent winner last Wednesday.)

NBC News and others called CA-21 for Republican David Valadao, but he leads by fewer than 500 votes, with thousands of votes remaining to be counted, per the Fresno Bee.

U.S. fires tear gas at migrants trying to cross the border

“American authorities used tear gas on hundreds of migrants who tried to enter the United States illegally Sunday, prompting officials to shut down operations at the border crossing between this city and San Diego, one of the busiest in the world,” per NBC News. “U.S. Customs and Border Protection suspended all vehicles and pedestrians from passing through the San Ysidro Port of Entry at 11:30 a.m. after the migrants tried to cross on either side of the inspection station. San Ysidro was reopened shortly after 6 p.m., the agency said. Some migrants said they tried crossing only after being denied access to the port of entry where they could claim asylum.”

Earlier this morning, Trump tweeted this response: “Mexico should move the flag waving Migrants, many of whom are stone cold criminals, back to their countries. Do it by plane, do it by bus, do it anyway you want, but they are NOT coming into the U.S.A. We will close the Border permanently if need be. Congress, fund the WALL!”

Russia seizes Ukrainian vessels in the Black Sea

But Trump has NOT tweeted about this developing story … NBC’s Alex Johnson: “Ukraine convened an emergency meeting of what it called its war cabinet on Sunday after it accused Russia of having fired on three of its vessels in the Black Sea, injuring at least six sailors. Russia's Federal Security Service, or FSB, confirmed that it had seized what it called three Ukrainian "warships," saying they had trespassed into Russian territorial waters. It said that "weapons were used to force the Ukrainian warships to stop" and that three Ukrainian service members were treated for minor injuries, TASS, the official Russian news agency, reported Sunday night.”

U.N. Ambassador Nikki Haley said that an emergency UN Security Council meeting has been called for today at 11:00 a.m. ET to discuss this situation.

By the way, Trump and Putin are scheduled to meet at the G-20 summit in Buenos Aires later this month.

GOP Sen: Trump’s Khashoggi stance is 'inconsistent with the intelligence I’ve seen'

On “Meet the Press” yesterday, Sen. Mike Lee, R-Utah, said he disagreed with the president’s pushback on the CIA’s assessment of high confidence that the crown prince of Saudi Arabia order the murder of journalist Jamal Khashoggi:

“I disagree with the president's assessment. It's inconsistent with the intelligence I've seen. Now look, I don't have access to everything the president sees. I'm not sure what he's relying on. The intelligence I've seen suggests that this was ordered by the crown prince.”

Trump administration tries to bury climate report the day after Thanksgiving

“A major scientific report issued by 13 federal agencies on Friday presents the starkest warnings to date of the consequences of climate change for the United States, predicting that if significant steps are not taken to rein in global warming, the damage will knock as much as 10 percent off the size of the American economy by century’s end,” the New York Times wrote on Friday. “The report, which was mandated by Congress and made public by the White House, is notable not only for the precision of its calculations and bluntness of its conclusions, but also because its findings are directly at odds with President Trump’s agenda of environmental deregulation, which he asserts will spur economic growth.”

“A White House statement said the report, which was started under the Obama administration, was ‘largely based on the most extreme scenario’ of global warming and that the next assessment would provide an opportunity for greater balance.”