It’s been nearly four weeks since the 2020 presidential election concluded and three weeks since the race was affirmatively called for President-elect Joe Biden. For President Trump and his most fervent supporters, though, we’re simply in some sort of postgame period during which the whole endeavor is adjudicated and rejiggered. There’s this sense, fomented by the president, that somehow something somewhere will shake loose and the resulting avalanche will push Trump to a second consecutive term in office.

That avalanche is entirely dependent on one claim: The results of the election are suspect due to alleged fraud.

That is a refrain that predates the election itself by months or years, with Trump alleging that he was the victim of fraudulent activity extending back to his first electoral loss in the Iowa caucuses in 2016. The only reason that there’s this still-burbling effort to figure out how to get Trump a win this year is simply that Trump set that expectation over and over before voting even began: There would be fraud, he claimed — and then, when he lost, he said that his prediction had come true.

Over the course of the weeks since the election, Trump’s campaign and legal team have failed to present the evidence that this purported fraud occurred. The president’s personal attorney Rudolph W. Giuliani claimed at a news conference earlier this month that the evidence would be presented in due time to the court. But — giving Giuliani the unwarranted benefit of the doubt — there’s no reason to wait. Publishing this purported evidence now won’t hurt any legal case, because it would be evaluated on its merits by Trump’s legal opponents are surely as it would be vetted by journalists.

So the moment has arrived. Trump and his boosters keep saying this proof exists and keep not delivering, undermining confidence in the election result. In all sincerity, if there was such substantial fraud that the outcome of the election was affected, it should be released now, and not held in abeyance for some unclear reason. (It's unclear why the campaign team has allowed itself to keep getting hammered for its weak case by judge after judge instead of simply presenting this alleged evidence.)

By way of reminder:

Things that do not count as evidence of systemic fraud

That Biden won more than 80 million votes. This was a historic number but, then, so was Trump’s 74 million (as of writing). It’s a function both of population growth and of enormous interest in an election that served as a referendum on the most polarizing president in history.

That there were sudden surges in vote totals that benefited Biden. As the election approached, there was a deliberate and obvious effort by Trump to cast suspicion, without evidence, on mail-in ballots. After the polls closed, those ballots were added to the results, with some states taking hours, others weeks, to announce the additional count. Since the mail-in ballots tended to favor Biden, many states’ results shifted in his direction. This was entirely a function of the order in which votes were counted and not of any change in the results. It was also expected.

Why were there sudden surges to benefit Biden? Because big cities with lots of votes — and which heavily preferred Biden — were reporting their results. Trump complained about a big batch of votes favoring Biden coming in early in the morning the day after the election. Those were Milwaukee's votes, where both Biden and Trump earned more support than Trump and Hillary Clinton had four years ago. It was only suspicious if you didn't understand what was happening or chose not to admit that you did.

That other suspicious-seeming things happened but don't actually show that fraud occurred. Humans are excellent pattern-seekers and can pick a pattern out of an entirely random set of events. There's even a word for it: pareidolia. Ever see a face emerge from a brick wall? That's pareidolia. There's no actual face there, but your brain is habituated to find patterns like that.

So just because there was a suspicious van that pulled up to a vote-counting center doesn't mean that anything more devious occurred than that a photographer was unloading his equipment. Just because staff covered the windows of a vote-counting center doesn't mean that something untoward was happening; they may have simply been trying to uphold a law preventing vote-counting from being recorded. Just because a lower density of mail-in ballots may have been rejected than in elections past doesn't necessarily mean that fraud occurred.

For months before the election, Trump told his supporters that every brick wall would have a face in it. That doesn't mean that every brick wall actually does.

That hundreds of people signed sworn statements about things they found suspicious. The Trump campaign collected hundreds of affidavits from people who had volunteered to observe vote-counting. These were sworn testimonials of what people saw, statements subject to perjury.

That doesn't mean they are proof of fraud. If I sign a sworn affidavit that you loaded a large TV into the back of a van, that doesn't mean you stole a TV. Particularly if it turns out that you run a TV-moving business and you do this all the time.

When city officials in Detroit addressed allegations made by the Trump campaign in a thick cluster of affidavits, that sort of misunderstanding was their central point.

“Most of the objections raised in the submitted affidavits are grounded in an extraordinary failure to understand how elections function,” the city said in a filing. A review of the affidavits in that case makes clear that there are almost no actual allegations of fraud but, instead, almost entirely activity that seemed suspicious to the uninitiated.

A large volume of accusations is not itself evidence.

That suspicious-seeming things didn’t happen. In the wake of the election, again mostly because of a pareidoliac effort to suss out anything fraud-adjacent to bolster Trump’s case, there have been a number of claims made about the vote that simply aren’t true.

It's not true, for example, that more absentee ballots were returned in Pennsylvania than were sent out. It's not true that big cities were suspiciously pro-Biden; in fact, some cities were more favorable for Trump than they were four years ago. (That includes Detroit.) Several of the examples of dead people voting highlighted by the Trump campaign were no such thing. A claim made by a postal worker in Pennsylvania about ballots being tampered with was later recanted.

The Post’s fact-checking team has rebutted a wide array of claims about fraud. If your evidence of fraud is something that has already been proved to be untrue, it is therefore not evidence of fraud.

The Post's Jon Swaine analyzes the Trump campaign's last-ditch legal attempts to get the result of the 2020 election overturned. (The Washington Post)

That isolated examples of fraud occurred. Asked by ABC News earlier this month, most states indicated that they had seen a few isolated incidents of apparent fraudulent activity. But scale is important here: Trump's team is alleging that tens of thousands of votes in multiple states were submitted fraudulently. That a guy in Pennsylvania tried to get a ballot for his dead mother is not evidence that thousands of people in the state did so successfully and without anyone noticing.

Scale is key. No one has ever said that no attempted fraud occurs, just as (to use my favorite analogy) no one says that auto theft doesn't occur. But a few stolen cars isn't itself evidence of a multistate ring of car thieves involving thousands of criminals who steal tens of thousands of cars at a time.

That there exist ways in which fraud could have occurred, even though there isn't evidence that it did. One of the ways in which Trump and his allies tried to undermine confidence in mail-in voting before the election was to conflate the possibility of things happening with the inevitability of them happening. That ballots were mailed out universally in some states became proof that those states would be subject to rampant fraud.

In the weeks since the election, we've seen a number of similar assertions, claims that because there may have been a route for people to submit a fraudulent ballot that they did so without detection at massive scale. The Trump campaign is claiming, at times explicitly, that there was a massive fraudulent scheme successfully leveraging loopholes to throw the election just enough in Biden's direction in just enough places.

To go back to the preceding analogy: that most Americans have screwdrivers that could be used to steal cars is also not evidence of a widespread conspiracy to undermine the system of car ownership in the United States.

The above includes allegations about voting machines changing votes without evidence that this occurred. A specific example of the preceding point is the claim from Trump’s former attorney Sidney Powell that vote totals could have been changed on electronic voting machines. There’s no evidence that this happened — and even claims that it could technically have been done aren’t evidence that it was. (The company being targeted by Powell et al. says that its machines can’t do that anyway.)

To use a non-technological example, it's possible to throw out every Trump ballot before it can be counted. That doesn't mean that any were, particularly in the absence of any evidence that they were.

As for Powell's more exotic claims about voting machines, those are either false, obviously irrelevant or both.

That “statistical analysis” suggests that vote totals were weird. There is unquestionably a useful role played by statistical analysis of votes that can illuminate possible problems with election results. But such analysis doesn’t by itself constitute proof of fraud, and such analyses can often be swayed by the analysts’s subjective views of the issue.

Others are simply ridiculous.

Things that do count as evidence of systemic fraud

Demonstrated examples of fraud affecting a large number of votes. This could be evidence of a large number of votes cast on behalf of a large number of dead people. It could be evidence of votes cast on behalf of hundreds of people who had no intention of voting. It could be evidence of a coordinated effort to do one of those things.

What constitutes evidence? Something that strongly suggests fraud occurred and that withstands scrutiny. Something that hasn’t been debunked and can’t easily be debunked. Sworn affidavits from, say, participants in such schemes or criminal investigations suggesting that the schemes existed.

To date, the Trump campaign has offered nothing meeting that not-very-high standard. It has instead relied upon the tendency of the president's base to assume that fraud occurred (thanks to Trump's own insistences) to allow it to simply say that it did. This has been Trump's own position — a wildly insufficient one. If there's evidence, show the evidence. If there isn't, admit it. To do otherwise is at best dishonest and, at worst, significantly damaging to the country.

Trump lost three weeks ago and hasn’t yet offered even a scintilla of evidence that he didn’t. There remains no reason to think that he will.