Calls among Hillary Clinton supporters for a recount of votes in three key states grew louder this week on the news that her national popular vote lead surpassed 2 million votes, along with reports of voter irregularities in some counties.

Last week, Clinton campaign chairman John Podesta spoke with a few election lawyers and computer scientists who urged him to ask for a recount in Wisconsin, Pennsylvania and Michigan because they thought the electronic voting booths used in those states could have been hacked, according to a report in New York magazine.

The academics said their findings showed Clinton's support had dropped 7 percentage points in counties that used electronic voting machines, as opposed to those counties that used optical scanners or paper ballots.

FILE - A voting machine is seen inside a VFW post FILE - A voting machine is seen inside a VFW post in Saukville, Wisconsin. FILE - A voting machine is seen inside a VFW post in Saukville, Wisconsin.

Though the academics provided no proof of any hacking, they nonetheless urged the recount based on the slim margin of Trump's victories in those states — less than 2 percentage points in all three states.

Foreign interference?

Had Clinton won these states, she would have earned 274 electoral votes, which is just slightly higher than the 270 needed to win the presidency.

In a Wednesday blog post on Medium.com, one of the academics, University of Michigan computer science professor J. Alex Halderman, said he thought it was possible a foreign government could hack America's voting machines. He called for an examination of the voting equipment in the three states for signs of a cyberattack.

"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," he wrote.

While the academics questioned the validity of the elections in the three Midwestern states, polling expert Nate Silver of the website FiveThirtyEight.com said the claim of rigged results in the states was probably false, and he said Clinton's loss could be attributed to demographic shifts.

Silver's explanation

According to Silver, the disparities noted in the New York magazine report "completely disappear" when controlling for race and education levels, two demographic indicators that most closely predicted the vote shift this year.

"Maybe a more complicated analysis would reveal something, but usually bad news when a finding can't survive a basic sanity check like this," he wrote on Twitter. "Nothing in Pennsylvania, either, whether or not you control for demographics. And Michigan has paper ballots everywhere, so not even sure what claim is being made there."

Despite the lack of evidence, Green Party candidate Jill Stein has so far raised $2.7 million — enough to pay for the recount effort in Wisconsin — and was attempting to raise an additional $2 million to request recounts in Michigan and Pennsylvania.

A post on Stein's campaign website called the voting machines used in Wisconsin "highly vulnerable to hacking and malicious programming," and said the machines lacked any security features.

FILE - A post on the website of Green Party presid FILE - Green Party presidential candidate Jill Stein speaks at a rally in Philadelphia, July 27, 2016. FILE - Green Party presidential candidate Jill Stein speaks at a rally in Philadelphia, July 27, 2016.

Stein's initiative

Stein won slightly more than 1 percent of the popular vote. The statement on her website said the recount effort wasn't meant to help Clinton, whom Stein heavily criticized throughout the campaign, but "is about protecting our democracy."

The deadline to ask for a recount is Monday in Michigan and Wednesday in Pennsylvania.

The Clinton campaign has yet to announce any plans to contest the results in the three states, but she and her supporters repeatedly denounced Trump during the campaign after he said he thought the election might be rigged against him.

"We are a country based on laws, and we've had hot, contested elections going back to the very beginning," Clinton said in October, after her final debate with Trump. "But one of our hallmarks has always been that we accept the outcomes of our election."

President Barack Obama made similar comments during the election, telling Trump to "stop whining" about a rigged election, and the president said it could never happen.

"There is no serious person out there who would suggest that you could even rig America's elections, in part because they are so decentralized," he said. "There is no evidence that that has happened in the past, or that there are instances that could happen this time."