Gabrielle Giffords huddled with Vice President Joe Biden in his private office just off the Senate floor on an April Wednesday in 2013, watching the defeat of a bill to expand background checks to most gun sales.
Giffords - a former Democratic lawmaker who still had difficulty speaking after being shot in the head in 2011 during an event in her Arizona district - was equal parts furious and devastated as she watched 46 of her former colleagues, including five Democratic senators, vote against the gun-control measure informally known as Manchin-Toomey.