Jimmy Carter helped expand democracy around the world long after he left the White House. His efforts gave rise to the Carter Center, which promotes fair elections as a vehicle for peace. It has monitored 125 elections in 40 countries and three tribal nations since it first started the work in 1989. David Carroll is head of the center’s democracy program. He says the former president had moral authority and credibility as someone who had both won and lost elections. That was essential to the trust people placed in him. Carter died Sunday at 100.