Carter the Chief Diplomat
To get votes, Carter made concessions to many senators.
Treaty Related Concessions
"The administration allowed all six reservations and seven understandings to the two treaties, in addition to the two leadership amendments.... But in dealing with non-germane concessions the reservations allowed the likes of Nunn, Bentson and Talmadge, the administration signaled a willingness to compromise, to make whatever trade-offs were necessary to ensure against critical defections." - Limits of Victory, George Moffat III, page 96
The Carter Administration was put in a delicate position to get DeConcini's vote (see document below).
Non-Treaty Related Concessions
"So he asked me a couple of questions about his book, and I could almost quote his book and I convinced him. And I believe that was one of the reasons later that he made a vote that has transformed life in Panama..." - Jimmy Carter