Does Hillary Clinton still have a path to the White House?

That’s the provocative question posed by some computer security experts, who think voting results in key states could have been manipulated by hackers.

The emphasis here is on “could.” There’s no clear evidence that voting machines were rigged or that ballots were altered, but as reported Tuesday night in New York magazine, a group of computer scientists and election lawyers has urged Clinton to call for a recount in Wisconsin, Michigan, and Pennsylvania, three swing states that Donald Trump won--to the surprise of just about every pollster, pundit, and journalist in America.

Clinton would have to win those states back in order to change the outcome of the election. And while it’s tempting to blame hackers, and not the failure of the political professional class, for Trump’s upset, experts warn not to get your hopes up for a shocking turnaround. For hackers to have changed the votes in three states would have been even more surprising than Trump’s victory.

“There is zero evidence of tampering right now. Zero,” David Becker, the executive director of the Center for Election Innovation and Research, told The Daily Beast. The simpler explanation for why the vote deviated from expectations and historical trends was that Barack Obama wasn’t at the top of the ticket. The results for Clinton “only look off when you compare them to the Obama elections” in 2008 and 2012, Becker said.

The hackers would have had to begin their work in advance of the election. And in those states or counties that don’t use electronic voting machines exclusively, they’d probably have to be on the ground, infiltrating elections offices, and working up to Election Day if not on the day itself. Throwing the votes in these three states on the same day would have required teams of people working in coordination with a high risk that they’d get caught, Becker said.

“I don’t know how you’d plan for something like this even if you had George Clooney and Brad Pitt,” he said, referring to the Oceans movie franchise in which talented thieves pull of absurdly implausible heists.

Even one of the computer scientists reportedly urging Clinton to call for a recount seemed to downplay the notion that hackers stole the election for Trump.

“Were this year’s deviations from pre-election polls the results of a cyberattack? Probably not,” J. Alex Halderman, a professor of computer science at the University of Michigan, wrote in a post on Medium. “I believe the most likely explanation is that the polls were systematically wrong, rather than that the election was hacked. But I don’t believe that either one of these seemingly unlikely explanations is overwhelmingly more likely than the other.”

“The only way to know whether a cyberattack changed the result,” Halderman continued, “is to closely examine the available physical evidence — paper ballots and voting equipment in critical states like Wisconsin, Michigan, and Pennsylvania. Unfortunately, nobody is ever going to examine that evidence unless candidates in those states act now, in the next several days, to petition for recounts.”

But that’s not entirely true, because in some states, officials routinely go back and look at vote counts in order to determine to determine that laws were followed and voting machines worked properly.

Wisconsin, a state that Halderman flagged, is one of them. There, the law requires a random audit of each type of voting equipment used in the state, of which there are about half a dozen from different vendors and manufacturers, Michael Haas, the administrator of the Wisconsin Elections Commission, told The Daily Beast.

“People go through and hand count the ballots and make sure that the equipment counted them as you’d expect based on how the ballots were marked,” he said. The elections commission will compile a final report by December 15 and provide it to an oversight body. Any petition to hold a recount is due by this Friday at 5pm. “We haven’t received any inquires from the Clinton campaign about a petition” to hold a recount, Haas said.

Becker said he was confident that the Wisconsin audit would detect any irregularities that could indicate vote tampering. “If there is a problem, we’ll know about it.”

But the auditing procedures in other states may give skeptics less comfort. In Michigan, there is no audit aimed at re-tabulating or counting ballots. Rather, officials conduct a review to ensure that local officials properly followed laws and procedures. Experts say it’s better than nothing, but isn’t a robust means for verifying that there were no shenanigans or errors on Election Day.

Michigan only uses optical scanning systems--voters make their choices on paper ballots that are tabulated by a machine. The state doesn’t use electronic voting machines, like those with touch screens that may rely on software downloaded from the internet, which could be vulnerable to tampering.

This doesn’t mean the election results couldn’t have been altered. But Fred Woodhams, a spokesperson for the Michigan Secretary of State, told The Daily Beast that the state has used the optical machines for more than a decade and that “time and again they have demonstrated their extreme accuracy and integrity.”

Official assurances count for something. But in the last state flagged by the researchers, Pennsylvania, it’s not clear that an audit would detect tampering in some parts of the state.

Pennsylvania is one of those states that gives election security experts heartburn, because the electronic voting machines it uses don’t print out a paper record of the voter’s selections. In effect, there is no way to verify that the machine accurately recorded the votes, experts say.

Experts have long pointed out that these paperless electronic machines would make a prime target for hackers. Pennsylvania does use paper ballots in some parts of the state, and it does conduct some post-election audits. But it could be difficult to detect tampering with the voting machines unless they’re directly examined.

A spokesperson for the Pennsylvania Department of State said in a statement that officials are “aware of the report” in New York magazine. “The Pennsylvania Election Code includes a provision allowing an election to be contested in the courts. Such action must be taken within 20 days after the election. We will not speculate or comment on any potential litigation.”

The statement made no mention of an audit.

The bottom line is that there’s no evidence yet of election hacking, but there’s also no universal policy to audit results after an election. And that’s unfortunate, because regular audits would help build confidence that elections went off smoothly and weren’t targeted by hackers, said Pamela Smith, the president of Verified Voting, a nonprofit group that advocates transparency and security in U.S. elections.

“My feeling is audits should be done as a matter of course,” Smith told The Daily Beast, adding that states that don’t conduct them now could launch “a pilot audit” as a sign that they take the issue seriously.

“A state could say, we know this was a contentious election, we have that unusual situation where the popular vote winner didn't win the most electoral college votes, what the heck, let’s do an audit. I think that’s a perfectly legitimate thing to do.”