But the new offensive could also backfire — as it did for Dean in 2004, when he attacked Gephardt over the Iraq War and Gephardt responded by hitting him from the left on trade and Social Security. The crossfire ultimately wounded them both, allowing John Kerry and John Edwards to finish ahead of them in Iowa.

“I think the Warren-Pete fight in Iowa is probably going to hurt them is the way that Dean-Gephardt ‘murder-suicide pact’ did,” Joe Trippi, a top strategist on Dean’s campaign, said ruefully.

At the same time, the Warren campaign has been trying to lower expectations in the final days of the fourth quarter as its grassroots fundraising slows. In several emails to supporters over the past week, the campaign has set a goal of raising $20 million, less than the $24.6 million she raised last quarter. Many staffers have tried to gin up extra donations with promises to sing songs, make memes, and write poems for donors that give a bit more.