The demoralization and fear gripping blue America in the early weeks of President Trump’s administration have left liberal groups and their allies struggling for cash, hurting their ability to effectively combat the right-wing transformation of the federal government.

The small-dollar online spigot that powered opposition to the first Trump administration has slowed to a trickle as shaken liberal voters withhold their donations.

Charitable foundations that have long supported causes like voting rights, L.G.B.T.Q. equality and immigrants’ rights are pulling back, devoting time to prepare for expected investigations from the Republican-led Congress.

And some of the country’s biggest liberal donors have paused giving, frustrated with what they see as Democrats’ lack of vision and worried about retaliation from a vengeful president. Some Democrats say a few of their reliable donors are now openly supporting Mr. Trump, or at least looking to curry favor with him.

Fund-raising slowdowns are common after a presidential defeat and before marquee midterm races fully begin. But interviews with more than 50 donors, strategists and leaders of activist organizations show that many Democrats believe this year is different.

While Mr. Trump has not taken action against any liberal groups or lawmakers, Democrats worry his frequent threats of retribution during the campaign have led to a chilling effect on the charitable foundations and nonprofit advocacy groups that have long been pillars of the country’s civil society.