It has been an unsettling week for some of President Trump’s political contributors.

On Tuesday, it was revealed that Stephen Ross, the billionaire real estate developer whose firm owns SoulCycle and Equinox gym, was hosting a big-money fund-raiser in support of Mr. Trump’s re-election campaign and the Republican National Committee on Friday, with ticket prices running as high as $250,000. This news did not sit well with many patrons of Equinox and SoulCycle, who took to social media to call for a boycott.

Lower down the donor ladder, 44 residents of San Antonio who had contributed the maximum legal amount to Mr. Trump’s re-election campaign found themselves in the spotlight, after their names were tweeted out on Monday by Representative Joaquin Castro, Democrat of Texas, who declared himself “Sad to see so many” of his constituents “fueling a campaign of hate that labels Hispanic immigrants as ‘invaders.’”

The particulars of these two episodes differed, as did the public reactions. But both touched on broader questions about the advantages and challenges of promoting campaign finance transparency in the age of social media.

Scrambling to contain the fallout from the fund-raiser news, Equinox and SoulCycle tried to draw a bright line between corporate policy and the personal politics of Mr. Ross. The companies posted statements on social media, dismissing him as “a passive investor” and assuring members that the companies are not involved with his fund-raiser, that “no company profits are used to fund politicians” and that they “believe in tolerance and equality.” Mr. Ross issued his own defense, insisting that he had always been “an active participant in the democratic process” and had “never been bashful” about airing points of disagreements with the president.