Davis was an early supporter of Barack Obama's 2008 bid for the presidency, and one of the national co-chairs for Obama's 2008 campaign. Known for his oratorical skills, Davis made one of the nominating speeches for Obama at the 2008 Democratic National Convention. While serving on the House Ways and Means Committee, Davis was the first African-American member of Congress to advocate that Committee Chairman Charles B. Rangel give up the chairmanship of the tax committee in the wake of ethics charges against Rangel. In 2009 and 2010 Davis, voted against the Patient Protection and Affordable Care Act, the only member of the Congressional Black Caucus to do so.