Reacting on The Colbert Report to the new congressional Republican majority’s vows to investigate the Obama administration, Abbe Lowell joked that he’d printed a lot of extra business cards — some blue, some red.

Lowell, who heads his firm’s white-collar criminal defense group in Washington, has represented dozens of members of Congress, lobbyists and government officials. A litigator for more than 20 years, Lowell is the go-to lawyer when it comes to constitutional issues stemming from leak investigations and prosecutions.