In the closely divided senate, Brett Kavanaugh's Supreme Court confirmation hinges in part on the votes of two moderate Republican senators: Lisa Murkowski of Alaska and Susan Collins of Maine.

For liberals concerned about what a seat for Kavanaugh would do to the court, Collins has been both a source of limited hope and frustration, expressing concerns about threats to Roe vs. Wade, while consulting with the Trump administration through the selection process.

So a group of liberal activists in Maine created an unusual crowdfunding campaign that encapsulated both of these emotions: they raised money in the form of pledges that they said they would give to whoever decided to challenge Collins in 2020 if she voted for Kavanaugh's confirmation. If she votes no, the money will never be withdrawn from donors.

"Senator Collins votes NO on Kavanaugh and you will not be charged, and no money will go to fund her future opponent," the platform notes. "Senator Collins votes YES on Kavanaugh and your pledge will go to her opponent's campaign, once that opponent has been identified."

The unusual fundraising effort by Maine People's Alliance, Mainers for Accountable Leadership and activist Ady Barkan on the platform Crowdpac had raised more than $1 million by Tuesday - a not insignificant amount for a political race in the small state. But amidst the attention it was receiving were signs that its efforts could be backfiring.

At least one ethics expert consulted by The Washington Post said that it may very well violate federal bribery statutes, which prohibit giving or offering anything of value to government officials in exchange for any acts or votes. And Collins issued a sharply worded response through a spokeswoman that called it an attempt at extortion.

"And anybody who thinks these tactics would work on Senator Collins obviously doesn't know her," spokeswoman Annie Clark said in a statement. "Senator Collins will make up her mind based on the merits of the nomination. Threats or other attempts to bully her will not play a factor in her decision making whatsoever."

Adav Noti, a senior director at the nonpartisan Campaign Legal Center, which works on rules of ethics and finance in government, told The Washington Post that he thought the listing was illegal, noting that bribery is a federal crime.

Other organizations that work at the intersection of money politics disagreed.

"It seems kind of icky but it doesn't rise to the level of bribery because there's no agreement," Jordan Libowitz, a spokesman for the Citizens for Ethics and Responsibilities. "It's just the way money and politics tend to work these days."

The two activist groups did not respond to a request for comment. Barkan did not immediately respond to a message left on his Facebook page.

The tone of the listing was alternately threatening and encouraging.

"The people of Maine are asking you to be a hero, Senator Collins," it noted, while warning that if she failed "to stand up for the people of Maine and for Americans across the country, every dollar donated to this campaign will go to your eventual Democratic opponent in 2020. We will get you out of office."

"Your card will only be charged if Collins votes for Kavanaugh's confirmation," the listing noted.

Collins has a reputation as a centrist though she is a mostly reliable Republican voter. She already backed Kavanaugh once, when he was nominated to the U.S. Court of Appeals by George W. Bush in 2006, and she has been sending strong signals that she will back him again this time around. After a meeting with him in August that she described as "excellent," she said that he told her he agreed that Roe v. Wade was settled as a precedent of the court.