Sanders advisors are targeting these party leaders and elected officials who have outsized influence in deciding who gets to be the Democratic nominee, and whom Hillary Clinton moved swiftly and aggressively to lock down early in the race. Each one of their votes at the convention in July is weighted as heavily as those of thousands of voters.

Clinton has 469 of them in her corner. Sanders has just 29.

Sanders advisors argue that if they can come close to catching Clinton in votes by the time the time the primaries conclude in June — even if they fail to overtake her — they will be able to persuade these lawmakers and other Democratic dignitaries to reconsider their loyalties to Clinton.