So-called "dark money" groups on the political left are planning how to spend millions to try to stop the confirmation of Brett Kavanaugh to the Supreme Court.

In an article headlined, "Liberal activists embrace ‘dark money' in Supreme Court fight," the Washington Post reported Friday how liberal groups are making use of unidentified donors to put out a slew of anti-Kavanaugh messages to persuade senators to vote against the federal judge's confirmation. Demand Justice is one such group, classified as a "social welfare" organizations by the IRS but able to keep its donors anonymous since it is housed inside another nonprofit.

Demand Justice executive director Brian Fallon, a former aide to Hillary Clinton, complained that pro-Kavanaugh groups will still outspend them. He said, however, that they are keeping up better in the fight against Kavanaugh, who President Donald Trump nominated to the Supreme Court earlier this month, than they did in their fight against now-Justice Neil Gorsuch last year.

"We'll still be outspent markedly, but probably 6- or 7-to-1 instead of 20-to-1 this time. That's important," said Fallon, a former spokesman for the 2016 Clinton campaign. "We're in a much better place by virtue of the fact that we're at least mitigating the chronic disadvantage in resources that usually is the case in these fights."

Demand Justice, which plans to raise and spend at least $5 million to oppose Trump's nominee, is airing ads in key states saying Kavanaugh, who currently serves on the D.C. Circuit Court, is a threat to abortion rights and to Obamacare. Trump nominated Kavanaugh to the nation's highest court after Justice Anthony Kennedy announced his retirement.

"Dark money" groups have become a target of criticism on the left ever since the landmark Supreme Court Citizens United decision in 2010, when the court ruled that corporations can spend unlimited money on political campaigns. Many Democrats have called for the decision to be overturned.

To swing the Kavanaugh vote, Demand Justice is focusing on Maine and Alaska, the homes of moderate Republican Sens. Susan Collins and Lisa Murkowski, respectively.

"These are very sophisticated campaigns that target individual senators [and are] almost surgical in nature," said Jonathan Turley, a constitutional law professor at George Washington University Law School.

Since judicial confirmations are not elections, groups required to spend most of their money on non-election activity are happy to pay for an enormous ad blitz.

"Spending money now on issues surrounding this judicial nomination free up funds to spend on electoral activity in the fall," said Republican campaign finance lawyer Charlie Spies. "Liberal groups spending $1 million on ads advocating against Kavanaugh in August frees up almost $1 million in capacity to run ads against Republicans in October."

Liberal groups opposing Kavanaugh are working hard to catch up to the Judicial Crisis Network, a conservative group that has spent millions supporting originalist judges around the country and has dropped $5.3 million to support Kavanaugh. The group says it fully respects Demand Justice and other groups keeping their donors secret.

"There's a reason we don't ask for their donors, and we have the same obligation to protect the confidentiality of our donors, as well," said Carrie Severino, chief counsel and policy director of Judicial Crisis Network.

Demand Justice gets its funding from the Sixteen Thirty Fund, a social welfare nonprofit that raises cash from undisclosed donors and spreads it to Demand Justice and other progressive groups.

Meanwhile, some Democrats in the Senate agree Kavanaugh is a grave threat. Sen. Cory Booker (D., N.J.) said supporting him is complicity in "evil," and Sen. Jeff Merkley (D., Ore.) said he will "pave the path to tyranny."

Kavanaugh's record has drawn widespread praise, however. Not only are conservatives and nearly every Republican senator supportive of his appointment, but a New York Times report found he was one of Harvard Law School's most beloved professors.