The activist, Leonard Leo, has been instrumental in pushing the federal judiciary to the right. A new tax filing offers a glimpse of the deep pool of money flowing into conservative causes.
The groups in the network spent nearly $504 million on policy and political fights, including grants to about 150 allied groups, between mid-2015 and last year.
After leading efforts to put conservatives on the bench, the activist has quietly built a sprawling network and raised huge sums of money to challenge liberal values.