Shortly after former vice president Joe Biden clinched the Democratic Party’s nomination for the 2020 presidential race, President Trump and his allies invested heavily in a particular line of argument. Biden was old and enfeebled, they asserted, and could barely function physically or intellectually.

Over and over, they made this argument, even releasing ads compiling snippets of Biden stumbling over words. There was no small irony to attacking Biden as old or prone to misstatements, of course, but it was the strategy they dropped like a blanket over the political conversation.

Then the Democrats held their convention and Biden was obviously not the caricature that his opponents had suggested. So Trump pivoted: Clearly, then, Biden was cheating.

Over and over again, this was the mantra. Biden was using performance-enhancing drugs of some sort, Trump claimed, demanding a drug test. It’s an extremely weird claim, presuming that Olympic-style rules should apply to everyday situations, and one without any evidence. (At a news conference on Sunday, Trump insisted that the claim could be proved if one were to “check out the Internet.”)

As Tuesday’s debate neared, the claim got more specific: Biden would be using an earpiece during the debate to take instruction from aides and allies. As of writing, it’s the top story on Fox News’s website; its on-air staff explored the subject early in the day. Trump’s campaign demanded that Biden reject the use of drugs and earpieces, a request that Biden laughed off. (“Biden campaign rejects Trump’s call for inspector to check candidates for listening devices at debate,” the main Fox headline currently reads.)

This is not the first such allegation in presidential debating. In 2004, some Democrats insisted that a weird puckering in George W. Bush’s suit jacket was an indicator of a hidden earpiece — as much a marker of an era before small, wireless, in-ear devices were possible as anything. In 2008, the same claim about Barack Obama. In 2016, the allegation was leveled against Hillary Clinton. Over and over, this assertion that one side (generally the Democrat) is cheating his or her way to success.

Consider, though, how this mirrors the Trump campaign’s election strategy more broadly.

What Trump’s team wants to do with these allegations is twofold. First, they want to disparage Biden as a cheater and untrustworthy. Second, they want to have an excuse for Biden doing better than Trump’s supporters might expect. That exchange in which Biden damaged Trump? Well, that was just because he had an earpiece or was on Adderall.

This is precisely what’s happening with Trump’s focus on mail-in voting. He and his allies are broadly asserting that such ballots can’t be trusted, despite the complete absence of evidence that there’s any broad effort to rig voting and the absence of evidence that any such scheme could work. Trump keeps insisting that Democrats are actively promoting absentee voting so the election can be stolen — a clunky effort to impugn his political opponents as cheats.

But, then, there’s that second reason: Insisting falsely that mail-in ballots are rife with fraud gives Trump an excuse for any loss. In the case of a close election, he can demand that states and counties stop counting these ballots that he’s convinced his supporters are necessarily suspect. (Again, importantly, they are not.) In the event that he is defeated more handily, the excuse instead will echo the one he made after he lost the popular vote in 2016. Then, he hinted at a massive, hazy effort to cast millions of illegal ballots, just enough that maybe some people would think he actually won the popular vote. Should he lose in November, he has already baked in that same excuse, and we can expect to hear ad nauseam about how he actually won the election if you discount mail-in votes.

What he’s doing with the debate and what he’s doing with the election are the same thing. In each case, he’s asserting that his opponents cheat, and in each case, that gives him the space to claim victory regardless of the outcome. Of course, we shouldn’t be surprised by this. It’s how Trump approaches politics in general, wildly disparaging his opponents and injecting as much uncertainty as possible about objective facts.

Biden’s team offered some accusations of its own as the debate neared. Deputy campaign manager Kate Bedingfield claimed that Trump stipulated the debate moderator not mention the number of deaths in the United States from the coronavirus.

Trump’s team responded quickly.

“This is a lie and it never happened,” his campaign’s communications director, Tim Murtaugh, wrote on Twitter. “This is the height of playing politics with a public health crisis. Biden is trying to distract from the facts that he won’t submit to an inspection for earpieces, won’t take a drug test, and needs multiple breaks during the 90-minute debate.”

Murtaugh has also repeatedly tweeted accusations about the dangers of mail-in voting.