Congress has the legal power to investigate Silicon Valley. Let's make it count | Zephyr Teachout

Lawmakers are about to undertake their first major antitrust hearing in 50 years. They should make tech companies squirm

In the last decision of the 2019-2020 supreme court term, Trump v Mazars, John Roberts outdid himself in being John Roberts. He authored a 7-2 decision in which he appears to stand up against Donald Trump's lawlessness, by clarifying that Congress can issue subpoenas for Trump financial documents. However, the congressional power is constrained by a new, vague, four-part test for courts to use in approving subpoenas for presidential documents. Roberts grandly reaffirmed congressional power to investigate the executive branch in theory, while making it harder in practice. He presented himself as the sober, rule-of-law judge, calling balls and strikes in the childish conflict between Congress and the executive branch - while giving himself more power.

Yet there's one big silver lining in Mazars: while shifting power from Congress to the courts in executive branch investigations, it gave Congress a huge green light for investigations into big corporations. According to the logic of the opinion, Congress is at the peak of its power when investigating economic behavior in service of prospective legislation.