Bernie Sanders Derides Pick of Clinton Allies as Convention Committee Leaders

Senator Bernie Sanders of Vermont is seeking to bar allies of Hillary Clinton from leading the powerful rules and platform committees of the Democratic National Convention in July, escalating his battle with party leaders.

In a letter sent on Friday to party officials, lawyers for Mr. Sanders said that the appointments of Barney Frank, the former Massachusetts congressman, and Gov. Dannel P. Malloy of Connecticut violated party rules. Mr. Frank is to co-lead th