Senator Paul Simon and comedian Al Franken rehearsing for a Citizen Action dinner honoring Simon at the Mayflower Hotel, Washington, D.C. Jamie Howren

Bob Kerrey, former governor of Nebraska, former U.S. Senator, and Medal of Honor recipient for his service as a Navy SEAL in Vietnam, speaks at the LBJ Presidential Library's Vietnam War Summit on Thursday, April 28, 2016. LBJ Library

Bob Kerrey, former governor of Nebraska, former U.S. Senator, and Medal of Honor recipient for his service as a Navy SEAL in Vietnam, speaks at the LBJ Presidential Library's Vietnam War Summit on Thursday, April 28, 2016. LBJ Library photo by David Hume Kennerly.