Donald Trump is preparing to argue that if he loses the presidential election on November 8, that’s only because it was “stolen” from him.

So if Trump does go down to defeat, Republican and conservative leaders across the country will immediately face a choice on November 9.

Do they play along with Trump’s bullshit, or do they tell their voters the truth — that he lost fair and square?

Now, this will be an incredibly important moment for democratic norms in the United States. Every losing major party presidential nominee in the modern era has recognized his opponent’s victory. The GOP has a responsibility to uphold that tradition for the stability of our political system.

But it’s not just abstract ideals, or hypothetical concerns about possible violence, that matter here. The future of the Republican Party also hangs in the balance, with the big question being: How great a role will Trump play in a post-election GOP?

Because if the GOP truly does want to free itself from Trump’s influence, its leading voices from both its establishment and conservative wings need to quickly and irrefutably reject the idea that the election was “stolen” from Trump.

If Hillary Clinton wins, then Paul Ryan, Mitch McConnell, Reince Priebus, Ted Cruz, Marco Rubio, Tom Cotton, and other Trump-supporting politicians and voices should say, loudly and clearly and repeatedly, starting on November 9, that she won fair and square.

That’s the right thing to do for the democratic system, and it’s also the smart thing to do for self-interested GOP players who want to ensure the blame for the party’s defeat goes where it rightfully belongs: to Donald Trump himself.

But if Republicans don’t do this — if they agree with the “rigged election” thesis or even just refuse to condemn it, hoping it will go away — they will prove that they truly are the party of Trump, and will ensure he remains a hugely influential voice in politics for years to come.

Trump will be vulnerable after the election

Republican voters and politicians have stood by Donald Trump for so long, in the wake of so many controversies, that it may seem they will necessarily side with him again if he argues that the election was stolen from him.

Yet right now, it’s genuinely unclear how much influence Trump — and Trumpism more generally — will have in the Republican Party on November 9.

Today Trump is the standard-bearer of the Republican Party, and the only person standing in between Hillary Clinton and the presidency of the United States. So naturally, most Republican voters, who loathe Clinton, tend to view Trump positively.

But in an encouraging sign for Republicans who hope that their party has not transformed permanently into the Trump Party, a Politico/Morning Consult poll conducted earlier this month shows only 13 percent of Republican voters would want to nominate Trump again in 2020 if he loses this year.

And this paltry level of support is just in response to a hypothetical Trump defeat. Once he has experienced an actual defeat, and is no longer standing in the way of a Hillary Clinton presidency but is rather being blamed for it, his popularity could drop even further.

So after the election, Trump will be vulnerable. He’ll lose much of his apparent power to tank the reputation of any Republican who defies him, like he did for Ted Cruz. The alternate reality he’s created for his supporters, where he’s cruising to victory — 69 percent of GOP voters think he’ll win, according to a recent Pew poll — will be revealed as a fraud. Republicans who want Trump’s influence will have a genuine opportunity to make the case against him.

Unless they fuck it up by letting him convince people that Clinton stole the election.

The two competing narratives to explain a Trump defeat

If Trump loses, there will be a blame game as two camps float competing narratives that explain his loss: one in which he’s a loser, and the other in which he’s a martyr.

Critics of Trump will hold that the GOP blew a perfectly winnable election by nominating him. Trump is such a loser that his loss tarnished the Republican Party and allowed the unpopular Hillary Clinton to win an election she probably shouldn’t have won, according to this narrative. Therefore, Republicans need to free their party from Trump’s toxic and damaging influence to position themselves to win the White House in 2020.

But there’s nothing Donald Trump hates more than being viewed as a loser. So he’s been preparing a narrative that will blame everyone but himself.

He’ll claim he was victim of a conspiracy orchestrated by malefactors in the media, the moneyed elites, and both parties’ establishments. This conspiracy, Trump is already alleging, has sabotaged his campaign in several ways, including by orchestrating “large scale voter fraud” in urban areas.

To be clear: Trump has no evidence of this whatsoever, and it doesn’t even make logical sense. “It would be literally insane to try to steal an election in the way Donald Trump is alleging,” law professor Rick Hasen writes at Slate. But a complete lack of evidence has never stopped Trump from throwing around accusations in the past, and it isn’t stopping him now.

The truth can set Republicans free ... from Trump

Since the primaries ended, the Republican Party has, for the most part, decided to accept Donald Trump, though various party members vary in their level of enthusiasm for the nominee.

RNC chief Reince Priebus has become a close ally, House Speaker Paul Ryan has vocally criticized him on certain topics but refused to rescind his endorsement, and Senate Majority Leader Mitch McConnell just doesn’t talk about him much. But they all support Trump’s candidacy, as do the vast majority of Republican politicians.

These politicians tend to argue that while Trump wasn’t their first choice, he was the choice of Republican voters as expressed in the primary process, and their will should be respected. They also tend to say that they’re supporting Trump as sort of a “lesser of two evils” choice over Hillary Clinton.

On November 9, both of those excuses will finally become irrelevant — which could inspire more leading Republicans to finally find the courage to take Trump to task.

Yet the problem is that Trump’s conspiratorial voter fraud narrative will surely be tempting for many Republican politicians. In many ways, it will be easier to pander to the base, to serve them the red meat they so crave, to tell them harrowing tales of Democratic perfidy, to delegitimize Hillary Clinton’s presidency in half the country from the get-go. And the most die-hard Trump fans will likely be convinced by his argument, though we don’t yet know just how large that group is.

The alternative is, simply, for these leading Republicans to tell the truth — that Trump blew a completely winnable election for the party.

Fundamentals-based models really do suggest that Republicans should have had a slight advantage this year. Hillary Clinton really is the second most unpopular major party nominee in modern times, behind only Trump. Trump really has run a terrible campaign. So the party has a real shot at discrediting him if they make this case during this particular moment.

But if enough Republicans instead decide to play along the myth that Trump was robbed — or even just to pay lip service to it — they’ll trap themselves inside Trump’s hall of mirrors for years to come.

Watch: This election is about normal vs. abnormal