For weeks, some current and former Sanders campaign workers have privately acknowledged feeling disheartened about Mr. Weavers determination to go after the Democratic National Committee, fearing a pitched battle with the party they hope to support in the general election. The intraparty fighting has affected morale, they say, and raised concerns that Mr. Weaver, a longtime Sanders aide who more recently ran a comic book store, was not devoted to achieving Democratic unity. Several described the campaigns message as having devolved into a near-obsession with perceived conspiracies on the part of Mrs. Clintons allies.
Democratic leaders said they wanted to do everything possible to avoid having Clinton-Sanders tensions send the Philadelphia convention into the sort of chaos they had expected to mar the Republican convention. So far, though, Mr. Sanders has not indicated that he would ask his delegates to support Mrs. Clinton, as she did in 2008 for Barack Obama.