Pressure is mounting from Hillary Clinton’s supporters for a recount of votes in three key states that Donald Trump narrowly won in the recent presidential election. Jill Stein, who ran for the presidency on the Green Party’s ticket, has raised close to $6 million in a crowdfunding campaign to initiate recounts in these states, and on Friday, filed for one in Wisconsin. On Saturday, Hillary Clinton’s campaign counsel, Mark Erik Elias said Clinton would join the effort, though he noted that their own investigation has not turned up any evidence of tampering. A reversal of the results in those states could, in theory, tip the election to Clinton. Could this actually happen? If so, how would it work? Would it even matter? Read on…

What was the final vote count?

Although the election was held more than two weeks ago, several states are still counting votes—mainly absentee and provisional ballots—and others have yet to declare their tallies certified and official. As of Saturday (Nov. 25), Clinton was leading in the popular vote, 64.6 million to Trump’s 62.4 million. That lead is insurmountable, given that there aren’t enough votes for Trump to surpass her.

Does it matter that Clinton won the popular vote?

Philosophically, maybe. But officially, no. According to Article II, Section 1 of the US Constitution, presidents are elected by electors, not a popular vote. Each state has a set number of electors, and Americans technically vote for a party’s slate of electors in their state, not directly for the presidential candidate. The 538 electors, divvied up according to the population of a state, cast their votes for the candidate on Dec. 19. They almost always follow the popular vote in their states, and some are bound by law to do so (or face fines if they don’t).

For all its flaws, the electoral college is the system the US uses to pick its president. At last count, Trump had 290 electoral votes to Clinton’s 232. Michigan’s 16 electors are still up in the air, given how close the count is there—just 10,000 votes difference, last we looked. But even if Clinton wins Michigan, she loses the electoral college 290-248.

Who is calling for a recount?

In this Medium post, Elias said Clinton’s campaign has received hundreds of messages, emails and calls urging them to do something to investigate claims the election results were hacked. New York magazine published an article this week saying that voting-rights lawyer John Bonifaz and J. Alex Halderman, director of the University of Michigan Center for Computer Security and Society, were “urging” Clinton campaign officials to call for a recount in Michigan, Pennsylvania, and Wisconsin. In Wisconsin, according to analysis by Bonifaz and Halderman, Clinton received fewer votes in counties that relied on electronic-voting machines compared with those that used optical scanners and paper ballots. The group “believes they’ve found persuasive evidence that results in Wisconsin, Michigan, and Pennsylvania may have been manipulated or hacked,” the magazine noted.

But Hillary Clinton did not lead calls for a recount—her campaign found no grounds for one. Instead it was Jill Stein, who won 1% of the popular vote, who began soliciting donations online to fund recounts in Michigan, Pennsylvania, and Wisconsin.

Is there evidence that electronic-voting machines were hacked?

Halderman then took to Medium Thursday to clarify:

“Were this year’s deviations from pre-election polls the results of a cyberattack? Probably not. I believe the most likely explanation is that the polls were systematically wrong, rather than that the election was hacked.”

Although there is no evidence of rigging, Halderman goes on to explain in alarming and important detail how easy it is to hack voting systems, how other recent cases of hacking establish plenty of evidence of intent to influence the US election, and why vote-count audits should be routine as a matter of sound public policy.

States that collect votes via machines without a paper trail are vulnerable to malware. Basically, it’s not that hard to hack into systems and trick them, on election day, into shifting the vote a few percentage points toward the candidate of your choice. “If my Ph.D. students and I were criminals, I’m sure we could pull it off,” Halderman writes.

Yikes!

Yep.

But, really, isn’t an attempt to hack the US election pretty far-fetched?

Not really. This summer, cyber-attackers broke into the emails of the Democratic National Committee and Clinton’s campaign manager. This revealed plenty of embarrassing material, and served as a wake-up call for how vulnerable online systems are.

Attackers also broke into voter registration systems in Illinois and Arizona, and stole voter data. Halderman cites other attempted breaches in several other states.

Why focus just on Michigan, Pennsylvania, and Wisconsin?

See above, about Wisconsin’s potentially suspect electronic-voting machines. The vast majority of Pennsylvania’s votes are tallied directly by machine, without a paper trail. Most importantly, the results in these states were incredibly close, with Trump’s winning by just 0.3% in Michigan, 1.2% in Pennsylvania, and 0.7% in Wisconsin. Together, those three states are worth a hefty 46 electoral college votes, enough to give Clinton the victory if they all transferred into her column.

What will it take to make a recount happen?

Well, Stein has already filed for a recount in Wisconsin. The deadlines for filing a motion to recount in the other two states are very soon: Pennsylvania (Nov. 28) and Michigan (Nov. 30). At the time of writing, Stein’s crowdfunding campaign had raised almost $6 million—enough to cover the filing fees, and close to the total $6-$7 million she anticipates it will take to pay for the entire recount process, mainly for lawyers’ fees and observers to oversee the process.

Could the election result actually be overturned?

It’s highly unlikely, even now that the Clinton camp has joined the effort. Her campaign says they don’t actually believe the election was hacked—they’ve joined Stein’s effort, they say, “to ensure the process proceeds in a manner that is fair to all sides.”

Meanwhile, in Clinton’s concession speech two weeks ago, she encouraged people to recognize that Trump “is our president.”

Of course, evidence of systemic hacking could change minds. But poll analyst Nate Silver is skeptical of the claims about Wisconsin—after running a few regressions, he says they ”can’t survive a basic sanity check.”

So should we all just accept it and move on?

Not necessarily. Elias notes that while Wisconsin and Pennsylvania conduct post-election audits, Michigan and many other states do not, which they view as “unfortunate.” “Every state,” adds Elias, “should do this basic audit to ensure accuracy and public confidence in the election.”

Halderman makes a similar case. After all, to have faith in the numbers we need to occasionally check the numbers. He writes:

“Examining the physical evidence in these states — even if it finds nothing amiss — will help allay doubt and give voters justified confidence that the results are accurate. It will also set a precedent for routinely examining paper ballots, which will provide an important deterrent against cyberattacks on future elections. Recounting the ballots now can only lead to strengthened electoral integrity, but the window for candidates to act is closing fast.”

Also, if there were regular election audits, it would preemptively pierce any conspiratorial thinking about the integrity of the electoral system.

Where does Trump stand on this? Can I blame him, somehow?

Recall, of course, the shock and horror when Trump said he would only accept the election result as genuine if he won. The system, he said, was “rigged.” It was brash and irresponsible and, sadly, classic Trump. But once he won, we were spared from further bluster about rigged elections, until Stein launched her fundraising pitch.

Trump could win over doubters, and confound expectations yet again, by taking Halderman’s very sensible advice and acknowledging that re-examining some potentially suspect votes could be a good thing. Few doubt the wisdom of bolstering democratic systems against determined, capable hackers, and there’s no time like the present for action. “Trust but verify” is a useful life-guiding principle.

Election audits should not be encouraged because Trump is president, but because democratic systems rely on fallible infrastructure, and now is as good a time as any to get serious about fixing it.

This post was updated to include the Clinton campaign joining Stein’s recount effort.