At an AFL-CIO convention this weekend, Massachusetts Sen. Elizabeth Warren called out the increasingly pro-corporate lean of the U.S. Supreme Court. Politico reports:

On the opening day of the AFL-CIO’s convention, Warren — the highest-profile national Democrat to address the gathering here — warned attendees of a “corporate capture of the federal courts.” In a speech that voiced a range of widely held frustrations on the left, Warren assailed the court as an instrument of the wealthy that regularly sides with the U.S. Chamber of Commerce. She cited an academic study that called the current Supreme Court’s five conservative-leaning justices among the “top 10 most pro-corporate justices in half a century.” “You follow this pro-corporate trend to its logical conclusion, and sooner or later you’ll end up with a Supreme Court that functions as a wholly owned subsidiary of Big Business,” Warren said, drawing murmurs from the crowd.

The study that Warren was referring to is a Minnesota Law Review study that found that the five conservative justices currently on the Supreme Court have sided with corporate interests at a greater rate than most justices since World War II. All five were among the ten most corporate-friendly justices in over 50 years. Justice Samuel Alito and Chief Justice John Roberts were the top two.

The Supreme Court majority’s consistent twisting of the law to put the interests of corporations over those of individuals is one of the main characteristics of the Roberts Court, but it is not the only extremely influential court with such a pro-corporate bent. In fact, the Court of Appeals for the District of Columbia Circuit, to which President Obama has nominated three highly qualified candidates, has been following the same trend, also because of the influence of judges named by George W. Bush. This is the court whose ultra-conservative justices declared that cigarette label warning requirements violate the free speech rights of tobacco companies and that requiring that employers inform employees of their right to unionize violates the free speech rights of the corporations.

While there is not currently a vacancy at the Supreme Court that could affect its balance, there are three at the DC Circuit. That is why Senate Republicans are working so hard to keep them empty.