Democrats trying to harness voter backlash against President Donald Trump have a new challenge: protecting their most vulnerable members from the headline-grabbing tactics of their most fervent activists.

Red-state Senate Democrats are staking their reelection bids on their ability to work with Trump. But the argument has gotten more complicated as the pushback against his policies becomes more personal. Rep. Maxine Waters’ (D-Calif.) call for liberals to accost Trump Cabinet members in public isn’t the kind of thing the party’s most vulnerable members, or even their leaders, want to answer for.

The Waters flap, after three Trump advisers got turned away or chased out of restaurants amid a nationwide furor over the president’s separation of immigrant families, underscores the risk Democrats face along with the reward of a fired-up base. They want to tap into liberal energy to drive their voters to the polls, but without engaging in the kind of tactics that will rile up Trump’s base and negate their advantage.