But those numbers alone aren’t what keeps some in the opposition up at night. Instead, it’s the notion that Mr. Trump is already running a general election campaign–targeting voters online, tailoring its messaging, and building a competitive grassroots army–as Democrats engage in a long primary battle that could see upwards of 20 candidates.

Additionally, Democratic donors and strategists are concerned about party candidates sidelining big donors and bundlers this cycle in favor of a grassroots approach–a trade that may be a winner politically but could be a fundamental hindrance long term.

“We’re not where we want to be right now…we need to ramp up fundraising,” says Democratic strategist Ben LaBolt, who served as President Obama’s campaign spokesman. “The fact is that for Donald Trump, the campaign is happening today…we can’t let him have an open playing field.”