Back when the Senate was considering the nomination of Brett Kavanaugh to the Supreme Court, activists in Maine engaged in an unusually direct effort to sway a presumed swing vote, Republican Sen. Susan Collins. They started amassing pledges for donations to her eventual opponent in 2020, to be collected only if she voted yes.If she voted against confirmation, no money would change hands. Ms. Collins cried foul, accusing the groups of crossing the line into outright bribery, and some ethics experts agreed. But really, wasn’t this just a less subtle version of what goes on all the time when people give money to politicians?

Case in point: the recent fundraiser a group of Korean-American merchants held for Mayor Catherine Pugh. This wasn’t about individuals expressing their appreciation for her leadership through their campaign contributions. On the contrary, many of the merchants involved own liquor stores in residential neighborhoods that are being targeted for possible closing through a rewrite of the city zoning code several years in the making. The effort began under former Mayor Stephanie Rawlings-Blake’s administration as an initiative of the health department, but Ms. Pugh has been if anything more outspoken about the deleterious effects of the over-concentration of liquor stores on public health and safety. She has called them magnets for crime and drug dealing and has targeted some of them for aggressive code enforcement as part of her Violence Reduction Initiative.

To put it mildly, she has not been a friend to their interests, and the fundraiser was a transparent effort to change that. One merchant spoke of the need to open a dialogue with the mayor; another said the event showed the ability of the Korean-American community to support politicians, as if the problem previously had simply been that they didn’t give to campaigns. A third said, “We’re asking for help. We’re begging. That’s the main reason to have a fundraiser.”

Ms. Pugh insists that neither these donations nor any others have any bearing on her policies. (Ms. Collins said the same thing and voted yes on Mr. Kavanaugh’s nomination; at last count, the fund for her as-yet-unknown opponent was creeping toward $4 million.) We’re willing to chalk up a report in the Korean-language press suggesting that Ms. Pugh would be willing to revisit the zoning code change to problems in translation; in her comments to The Sun’s Ian Duncan, she remained resolute in sticking to a deadline of next June for the stores in residential zones to close, change their business model or receive an exemption.

That’s good because the social science behind her linkage of crime with the over-concentration of liquor stores is rock solid. So is the evidence of bad health outcomes and reduced life expectancy. These licenses have been non-conforming uses under the zoning code for going on 50 years, and it’s been seven since the city first moved to shut them down. This is a clear case in which the city is pursuing a legitimate public interest while being fair to private ones.

Nonetheless, this episode reinforces the wisdom of Baltimore voters in enacting a charter amendment this year paving the way for public financing of campaigns for city offices. Now the City Council needs to follow through with a funding source and specific rules that will give voters the option of backing candidates whose campaigns are funded by small-dollar donors rather than deep-pocketed interests. That may well prove to be the hard part, but it’s essential to fostering public trust in government. Mayor Pugh may insist that donations from lobbying groups don’t affect her decision-making at all, and we certainly hope that proves to be true in this case. But wouldn’t it be better if no one even had to ask the question?