Let’s imagine it’s November 7 and the Republicans have the night before lost 20 seats in the House of Representatives, but still maintain control. Feeling vindicated, President Trump immediately fires Jeff Sessions, Rod Rosenstein, and federal prosecutors in New York, and Rosenstein’s replacement fires Robert Mueller.

The president is emboldened to move as the nation’s first authoritarian president against law enforcement, the press and anyone else who stands in his way. Relieved Republicans on Capitol Hill kill Obamacare, gut remaining environmental protections, bring back water-boarding, and build Trump’s wall.

"If Republicans win, that's the ballgame,” former Vice-President Walter Mondale, a normally unflappable guy, told columnist Albert Hunt last month. “If Trump can claim ‘the public has spoken, and they are for me,’ we're in real trouble.”

According to the conventional wisdom, this won’t happen. The combination of a natural tilt toward the out-of-power party, greater enthusiasm on the Democratic side, and Trump’s horrific performance in office will add up to a blue wave, or something close to it. Trump will be checked.

This is probably right. Probably. The consensus among experts is that the Democrats have about a 60-70 percent chance of winning the 23 House seats necessary to wrest control of the House from the Devin Nuneses of the world. I don’t know about you, but I don’t like those odds. Remember how wrong the Labor Day polls were in 2016? Remember how sure we all were after the Access Hollywood tape that Trump was toast?

Winning—and saving the republic—requires victories in more than half of the seats currently declared “toss-ups.” That won’t be easy, especially since the Koch Network and a tiny band of other GOP mega-donors are investing more than $100 million in Republican candidates after Labor Day, neutralizing the financial advantage Democrats have built in several races. Republicans are already way ahead in financing critical state legislative contests (which also helps their House candidates) and, inexplicably, in cutting-edge digital advertising.

It’s a truism that this election is about turnout. In the 2010 and 2014 midterms, millions of Democrats—especially young voters and minorities, but plenty of others—didn’t show up. These so-called “sporadic” voters—who vote in presidential years only—must be brought back to the polls in large numbers if the Democrats are to capitalize on their momentum.

The burden for making this happens falls not just on the Democratic Party but on you. By “you” I mean the reasonable American voter—Democrat, Republican, independent—who wouldn’t sleep well on November 7 (and beyond) knowing that Trump and the GOP have been validated. The big questions are these: Are you scared enough yet to be running scared? Have you got more important things to do for the next ten weeks than pitch in?

Most anti-Trumpers I meet are fairly aware of the stakes. They know that if Democrats win the House, they will have the subpoena power necessary to hold Trump accountable—to impeach him or at least pick up the investigations into Trump where Mueller leaves off if he gets fired. They understand at some level that Democratic control of the gavel means they can stop almost any horrendous thing the Trump Administration tries to do. And they intuitively get the consequences of falling short in the House—that what Trump has done so far will look like patty cake.

“ The fate of the United States rests on how many good people not only vote but “embrace” that “awesome heritage” by working hard to protect the country from a president bent on destroying it. ”

Some are opening their wallets, which is critical in congressional races where historically the candidates who spend more, win. Others are rolling up their sleeves in their own communities or flippable districts nearby. An umbrella organization called Indivisible has marshaled more than 6,000 grassroots groups across the country, at least two in every congressional district. NextGen America, funded by billionaire Tom Steyer, is pouring at least $30 million into mobilizing and registering college students as they return to campus. In Texas, Beto O’Rourke has more than 10,000 volunteers, which is a big reason why he’s within the margin of error against Ted Cruz in their Senate contest. About a dozen House Democratic candidates already have potent field organizations.

All of this is necessary but not sufficient. Too many Democrats are wringing their hands, not ringing their neighbors’ doorbells. The siren has sounded: It’s all hands on deck. But I worry that most progressive voters are idling in their bunks, obsessing over the latest cable news outrage. They think if they’ve “liked” this article, that’s enough for today. They write a small check to a candidate or two, and don’t know what else to do.

I’ve begun a little ritual where I ask impassioned anti-Trump Democrats to name the Democratic House candidates running in flippable districts in their states. These are smart, well-informed people I’m putting on the spot. Few can name more than one, if that. Others don’t even know who’s on the ballot in their own districts.

It’s not as if the Democratic candidates in flippable districts aren’t worthy of their support—that they cannot in good conscience support them financially or through phone banks and canvassing. These candidates are mostly impressive, effective, and disciplined, especially when it comes to focusing on resonant issues in their districts. Few will be pulled into the trap Republicans have laid for them by calling for impeachment before Mueller issues his report, or by endorsing the abolition (as opposed to the necessary restructuring) of ICE. They are doing what it takes to win.

The problem is that too many rank-and-file Democrats still don’t know exactly what to do to help them. They don’t understand that they can’t wait for the usual get-out-the-vote operation three days before the election. Those efforts only pay off if Democratic voters have been identified through canvassing or phone calls weeks or months before. In other words, some of the most important work for taking back the House is taking place right now. This year, and for the foreseeable future, field organizing and social media are more important than old-fashioned TV ads.

The good news about a “turnout election” —as opposed to a “persuasion election”— is that volunteers for Democratic candidates will not usually need to undertake the herculean task of trying to convince Trump voters to change their minds. That makes the block-walking much more pleasant. In fact, the volunteers I’ve interviewed this year have found that once they figured out the flippable districts they live in or near, the experience of working precincts with like-minded citizens on behalf of good candidates and progressive values is a positive, even inspiring, outlet for their anxiety about the condition of the country.

Recall the recriminations after 2016: How could Hillary Clinton not have gone to Wisconsin? This time the culprit could be the person in the mirror, even if you don’t live in a flippable district. How could New Yorkers not have gone to Staten Island to help Max Rose? How could Chicagoans not have gone to the Western suburbs to help Sean Casten? How could California, Pennsylvania, New Jersey and Ohio Democrats—and people of good will in several other states— not have done everything they could to flip seats nearby?

Future generations may ask: What did you do to stop Trump, Mommy? Was it really more important to walk the back nine than the 9th district, Daddy? College students may ask themselves if that tailgater on Saturday was a better use of their time than registering other students. When the Democratic House candidate in your area loses by 500 votes and the party falls one seat short of regaining control, and three months later Obamacare is repealed by three votes, you’re not going to feel so good saying, ‘Hey, at least I voted.” Or “I’ve still got the pink hat in my closet from the Women’s March.”

“We are citizens of a republic made of shared ideals,” John McCain wrote in his last book. “Even in times of political turmoil such as these, we share that awesome heritage and the responsibility to embrace it.”

This is the most important midterm election in American history. The fate of the United States rests on how many good people not only vote but “embrace” that “awesome heritage” by working hard to protect the country from a president bent on destroying it.