John Roberts is the Chief Justice of the Supreme Court. He's served this position since 2005, when he was nominated by President George W. Bush. Prior to assuming his role on the Supreme Court, Roberts was a judge on the D.C. Circuit after George W. Bush appointed him there in 2003.

Roberts has also served two Republican administrations--Ronald Reagan and George H.W. Bush. Outside of his government positions, Roberts predominantly worked as a lawyer in private practice for Hogan & Hartson. This firm has provided lobbying services on behalf of Koch Industries.

As highlighted in a brilliant piece by Jeffrey Toobin in the New Yorker, Justice Roberts was the key orchestrator in expanding the scope Citizens United v. Federal Elections Committee, and thus, enabling the court to overturn McCain-Feingold Act on campaign finance. This decision has opened the door for unprecedented corporate financing and advocacy in U.S. elections.

In 2010, after initially recusing himself from a case involving pharmaceutical giant Pfizer, Inc. because of his financial interests in the company, Roberts sold his Pfizer stock so he could take part in the decision.  The case revolved around whether those that suffer vaccine injuries can ever, under any circumstances, sue pharmaceutical companies.

In February 2011, the court ruled in a 6-2 decision that vaccine manufacturers are not liable for vaccine-induced injury or death, as long as they are "accompanied by proper directions and warnings." Roberts voted in favor of this decision.