WASHINGTON - Sen. Susan Collins' announcement Friday that she would vote "yes" on Supreme Court nominee Brett Kavanaugh likely ended the uncertainty over his confirmation.

But while Collins spoke on the Senate floor and explained why she would be voting for Kavanaugh, people angry over her decision were donating cash to defeat her in her next election.

More than $50,000 was given over the course of her nearly 45-minute speech, bringing the total raised on an online crowdfunding campaign to defeat Collins in her 2020 election to more than $3 million as of 7 p.m.

The campaign by three activists groups, Be A Hero Team, Maine People's Alliance and Mainers for Accountable Leadership, had been criticized by Collins and others over several weeks as a possible attempt to bribe Collins into voting against Kavanaugh.

The groups started raising money in August, asking people across the nation to donate to Collins' opponent in an attempt to show her the stark opposition to Kavanaugh. No one has yet filed to run against Collins in 2020. Susan Rice, former President Barack Obama's National Security Adviser and United Nations Ambassador, suggested on Twitter Friday that she could challenge Collins.

The donation page, titled "Either Sen. Collins VOTES NO on Kavanaugh OR we fund her future opponent" went down briefly on crowdfunding website crowdpac.com Friday afternoon because of "overwhelming" traffic to the page, Be a Hero said in a statement. The groups are also raising money on the website ActBlue and say in total, between the two the amount has topped $3 million. The groups say donations are coming in every three seconds.

More:Sen. Susan Collins a 'yes' on Kavanaugh, drawing anger from protesters and praise from GOP

More:Brett Kavanaugh moves towards Supreme Court confirmation after Susan Collins, Joe Manchin pledge support

The page has said those donating wouldn't be charged if Collins voted no on Kavanaugh. But on Friday, Collins seemingly put an end to the uncertainty, giving a nearly 45-minute speech on the Senate floor that explained her process and why she'd be voting to confirm him.

"Susan Collins has betrayed the people, and especially the women and survivors, of Maine," the campaign organizers said in a statement. "Thousands of Mainers wrote, called, visited, protested, begged and pleaded with Susan Collins to do the right thing - to be a hero - and vote no. She ignored them."

The statement continued, "For years she has claimed to be an independent, a different kind of Republican, but today she shattered that facade forever. Her vote will reverberate long after she has left the Senate."

The organizers said they were committed to defeating Collins in 2020 and pledged to "never let her forget" this decision.

"Maine deserves a Senator who would recoil at the idea of confirming a proven liar, an emotionally unstable partisan, to the Supreme Court," the statement said. "Maine deserves a Senator who will believe survivors, who will listen to their stories, and who will represent them with honor. Susan Collins is no longer capable of that."

During her speech on the floor, Collins went through the issues, from Obamacare, same-sex marriage and abortion rights, and said Kavanaugh's record and pledges before Congress were enough to keep her vote.

She said Christine Blasey Ford, who alleged Kavanaugh sexually assaulted her when they were teens, offered a compelling testimony before Congress, but ultimately no one could vouch for her claims or even remember the party.

Collins said the allegations, in her eyes, "fail to meet the 'more likely than not'" standard. She said she believes voting against Kavanaugh without witnesses or proof could start a "dangerous" precedent.

"I do not believe that these charges can fairly prevent Judge Kavanaugh from serving on the court," Collins said, adding that her decision should not be "misconstrued as suggesting that unwanted sexual contact of any nature is not a serious problem in this country."

A watchdog group asked the Justice Department to investigate the campaign against Collins out of concern the money donated was an attempt to bribe Collins' vote and called it illegal.

It's illegal if "the payments are made in return for an explicit promise or undertaking by the official to perform or not to perform an official act," the Foundation for Accountability and Civic Trust (FACT) wrote in a letter to the Justice Department.