From the Center for Responsive Politics:

A secretive network spending millions of dollars to confirm President Donald Trump’s Supreme Court picks terminated multiple 501(c)(4) nonprofit nodes last year while funneling money to an even more opaque limited-liability company, further obscuring the network’s funding sources.

At the crux of that network is Leonard Leo, Trump’s top outside judicial adviser and a longtime executive at the Federalist Society who helped shepherd Trump’s Supreme Court picks through the confirmation process. Leo holds leadership positions with multiple groups in the network.