This story was written by David Sirota and Andrew Perez.

The conservative dark money group that led the fight to install Brett Kavanaugh on the U.S. Supreme Court received nearly $16 million from a single mystery donor, according to IRS documents obtained by TMI.

The documents show that the Judicial Crisis Network (JCN) received a total of nearly $30 million of donations in between July 2018 and June 2019 -- the period that covered Kavanaugh’s tumultuous confirmation. In addition to the $15.9 million donation from a single donor, the group received five other 7-figure donations from anonymous sources.

JCN financed millions of dollars of ads promoting Kavanaugh. The new tax documents show the organization paid more than $12.3 million to a media buying firm during the tax year. Those documents also show that the organization funneled money to a number of other conservative groups that backed Kavanaugh’s confirmation. Those include $1 million to the National Rifle Association and $600,000 to One Nation, which both aired ads supporting Kavanaugh.

JCN does not disclose its donors. The group is closely linked with Trump’s top judicial adviser Leonard Leo, the longtime executive vice president of the Federalist Society, which is an influential Washington-based legal network for conservatives and libertarians. JCN paid nearly $1.2 million to BH Group LLC, a company affiliated with Leo.

Kavanaugh’s confirmation was hardly a sure thing -- he not only had what critics called an extreme judicial record, he also faced sexual assault accusations from Stanford professor Christine Blasey Ford, as well as questions about his personal finances. The well-funded campaign behind him was pivotal in overcoming those controversies and pressuring lawmakers to approve his nomination.

Kavanaugh replaced swing-vote Justice Anthony Kennedy -- and since he has joined the court, he has provided a reliably conservative vote on close 5-4 rulings. Most recently, he wrote the opinion for a 5-4 ruling that helps prevent workers from suing over allegations that Wall Street firms have bilked their retirement systems.