Earlier this year, all Democratic state party chairs sought to draw a sharp contrast with Republicans by backing a pledge to rule out the use of such tactics. Supporters viewed it as a basic first step to shape the tone of political discourse in the primary and guard against manipulation and online disinformation.

But party leaders did not bring the proposal to a vote at a meeting of the full DNC in San Francisco late last month, despite the pleas of the state chairs. Among the sprawling Democratic presidential field, only frontrunner Joe Biden has signed the pledge. The pact also calls on campaigns to publicly implore their supporters not to use disinformation and call them out if necessary.

“I haven’t the faintest idea” why it wasn’t taken up, said Tina Podlodowski, chairwoman of Washington state’s Democratic Party. “I’m kind of banging my head against this wall that has three letters — DNC — on it.”