SEATTLE -- Three weeks after the election, Donald Trump has officially been declared the winner in Michigan.

But Green Party candidate Jill Stein says 'not so fast.' Her campaign is planning to call for a recount in that state after filing similar petitions in Wisconsin and Pennsylvania.

A recount would not directly benefit Stein. So what’s behind the effort that’s already raised millions of dollars?

“The motivation has to do with election integrity. It’s not about overturning the election or who won. It’s 'were the votes counted?'” said Seattle Stein supporter Jody Grage, who worked on the Green Party’s presidential campaign.

“The motivation is that if we don’t start speaking up about the election, the difficulties, and the irregularities… it certainly isn’t going to get any better,” she continued.

"We need a system that is resilient, that is not open to tampering, and that includes automatic reassurance -- that specifically being an audit, an automatic audit,” Stein told NBC News in an interview on Sunday.

“This is what the voters are asking for. Donald Trump himself expressed concerns about the rigged political system, and he had enormous resonance with that. To my mind, we haven't proven rigging or unrigging based on who won. You prove rigging or unrigging based on examining the process and making sure that it has integrity,” Stein also said.

The Stein campaign, citing concerns over hacking and elections tampering, has raised more than $6 million as of Monday evening to launch recount efforts in multiple states.

The campaign says if it raises more money than needed, surplus funds will go toward “election integrity efforts and to promote voting system reform.”

Stein’s website estimates the average donation at $45.

“It's not like there's just a few big donors. This is a lot of people, there are Greens, Independents, Democrats, probably some Republicans too who really feel that voting integrity is a cornerstone of our system,” said Grage.

Elections officials maintain there's been no evidence of hacking or voter fraud. The Clinton campaign, which is now supporting the recount effort, acknowledges the recounts are not likely to change the outcome. Analysts say the chances are near impossible.

However, Clinton lost the three states involved in the effort by a little more than 100,000 votes combined -- narrow margins that helped Trump clinch the Electoral College win. So, do Stein supporters regret not backing Clinton?

“Heavens no. We are investing our vote in the future,” said Grage of the Green Party and alternative party candidates.

Meanwhile, President-Elect Trump took to Twitter Sunday to allege voter fraud in Virginia, New Hampshire, and California -- all states Clinton won.

Trump also claimed he was losing the popular vote because of “voter fraud and millions of illegal votes.”

California’s Secretary of State Alex Padilla fired back via Twitter, calling Trump’s claims absurd.

“His reckless tweets are inappropriate and unbecoming of a president-elect,” wrote Padilla.