In a tweet on Monday, President Trump endorsed Mitt Romney to fill the U.S. Senate seat left open by Utah's Orrin Hatch. The civil tone was different from the 2016 presidential campaign, when the men launched insults like “con man” (Romney) and “loser” (Trump).

Daniel Ellsberg strengthened public opposition to the Vietnam War in 1971 when he leaked the Pentagon Papers to the New York Times.