sympathized with the families affected by the explosion and had referred the matter to Senate lawyers. When he was subpoenaed to testify in the case, Chambliss claimed "legislative immunity." Chambliss defeated Martin 57% to 43% in the runoff election. Tenure Chambliss was first elected to the U.S. Senate in 2002. As a senator, he chaired the Senate Committee on Agriculture, Nutrition and Forestry during the 109th Congress (2005–2007). During the 112th Congress (2011–2012), he was the ranking Republican on the Senate Select Committee on Intelligence. Although Chambliss had a conservative voting record, he participated in bipartisan legislation—such as the 2007 Farm Bill, the bipartisan immigration reform (led by John McCain and Ted Kennedy) in 2007 and the Emergency Economic Stabilization Act of 2008. He was also the Republican leader of the Gang of 10, a bipartisan group which worked to create a compromise surrounding the energy policy of the United States. In December 2011, the Washington Post named Chambliss as one of the Best Leaders of 2011 for his attempts to craft a bipartisan deficit reduction package. On March 6, 2013, Chambliss was one of 12 Senators invited to a private dinner hosted, and personally paid for, by President Obama at The Jefferson Hotel. That same night, Chambliss participated in Rand Paul's filibuster over the government's use of lethal drone strikes—forcing the Senate to delay the expected confirmation of John O. Brennan to lead the Central Intelligence Agency. In April 2013, Chambliss was one of forty-six senators to vote against a bill which would have expanded background checks for all firearms buyers. Chambliss voted with 40 Republicans and five Democrats to stop the passage of the bill. Chambliss received bipartisan criticism in 2013 after discussing the "hormone level created by nature" as a possible cause of sexual assault in the military. In January 2014, Chambliss signed an amicus brief in support of Senator Ron Johnson's legal challenge against the U.S. Office of Personnel Management's Affordable Care Act ruling. Chambliss's son, Bo, was a registered lobbyist for the Chicago Mercantile Exchange. Bo Chambliss lobbied on commodity futures trading issues that fell under legislative jurisdiction of the Senate Agriculture Committee, of which the Senator was a member. Sen. Chambliss's office enacted a policy that prevented Bo Chambliss from lobbying the Senator or his staff. Chambliss did not seek reelection in 2014. Days after his retirement from the Senate in 2015, it was