So what happens now that Mr. Trump is no longer in power? In a political landscape defined by web advertising, social media campaigns and, yes, online fund-raising, many Democratic analysts and strategists are wondering whether they’ll be able to stir up the same kind of financial support.

“Donald Trump and his policies motivated a lot of giving to progressive organizations,” Mark Mellman, a longtime Democratic pollster and strategist, said Thursday in a phone interview. “Whether that will be sustained is an open question.”

Seeking answers, Mr. Mellman and Chuck Pruitt, another veteran Democratic consultant, last month undertook a private survey of donors to a wide array of left-leaning organizations and Democratic campaigns. This week, they presented the results on a Zoom call with representatives from various organizations and Democratic groups.

It also discovered that donors to these left-leaning groups had become more strongly partisan, with almost two-thirds of respondents to Mr. Mellman and Mr. Pruitt’s survey identifying as Democrats. That number has steadily climbed over the years: Back in 2007, after Democrats won control of the House as many voters lost faith in President George W. Bush, Mr. Mellman and Mr. Pruitt found that only about half of these kinds of donors were Democrats.

Mr. Mellman and Mr. Pruitt have undertaken studies like this at various moments since the 1990s, usually at what Mr. Mellman calls “serious inflection points” in national politics — “when the potential for giving and activism may change.”

It’s worth noting that these studies don’t use what is known in the polling industry as a probability-based model, so their results are subject to forms of error that more scientific surveys wouldn’t be. Still, their results can be revealing.

The share who said they planned to increase their giving tapered down to nearly zero.

But Mr. Mellman isn’t hugely concerned. This year’s study found one change from four years ago that he said was particularly heartening for his clients: Just as grass-roots donors to liberal causes have grown more partisan, they’ve also grown more positive about the Democratic Party and its leadership.

Close to half of all donors expressed a positive view of the Democratic Party, and a wide array of top Democratic officials received broadly favorable ratings from the survey’s Democratic respondents. Those include establishment politicians like President Biden and Senator Chuck Schumer, the majority leader, as well as left-wing figures like Representative Alexandria Ocasio-Cortez and Senator Bernie Sanders.

“There was a time when people were really dissatisfied with the party, this leader or that leader,” Mr. Mellman said. “That is not the case. There is admiration for the party, and nearly universal admiration for the whole range of leaders.”

He added, “It’s not the case that any one faction has a hold on these donors.”

The study also revealed that anxiety about Mr. Trump’s continued influence on Republican politics remained a concern for many left-leaning donors. And that Representative Marjorie Taylor Greene — a former QAnon supporter and staunch Trump defender, whom Democrats stripped of her committee posts this year — was nearly as well known and as intensely disliked as the former president.

“Trump and Trump’s policies motivated a lot of gifts — and people recognize that he’s gone. But there is still intense antipathy toward his supporters,” Mr. Mellman said.