GOVERNMENT-TRANSPARENCY activists sued the Trump administration Monday, demanding the release of records showing who has visited the White House, when and for how long. It’s not clear the activists have the better side of the legal question, which revolves around whether the visitor logs are Secret Service records subject to the Freedom of Information Act or White House records shielded from public transparency standards. But there is no question about how President Trump should respond. Under a 2009 settlement with these activists, the Obama White House disclosed the visitor logs for the rest of President Barack Obama’s time in office; Mr. Trump should disclose his also.

The Obama administration released some 6 million visitor records over two terms, offering a picture of the daily rush of advisers, lawmakers and petitioners granted access to the president, the first lady and staff across the executive mansion’s grounds. Using this information, The Post noted that the Obama White House met with a variety of lobbyists — connected to everything from the meat industry to Wall Street — on a single sample day in 2012. That same year, the New York Times found that, along with the flood of lobbyists, “those who donated the most to Mr. Obama and the Democratic Party since he started running for president were far more likely to visit the White House than others.” It was undoubtedly in the public interest for Americans to know who was attempting to peddle influence and when. Former Obama officials say that the policy discouraged staff from taking meetings that they should not have.

Some other former presidential advisers argue that these benefits come at too high a price. People who would otherwise offer valuable advice might shy from visiting the White House, so as not to appear on a public registry. In times of crisis, the president should feel uninhibited from seeking counsel. Emergency or no, one can imagine a variety of tough scenarios: Foreign dissidents, for example, might benefit from a private meeting with the president or West Wing staff, but would not be eager to send a public statement of association with high-level U.S. officials.

Former Obama administration staffers nevertheless report that, though releasing visitor logs led to some negative news articles, staff generally did not feel inhibited from arranging worthwhile meetings or getting good advice. Obama officials maintained a national security exception from the visitor log reporting program, the continuation of which would allow Mr. Trump and his staff to meet with sensitive sources or seek help in times of emergency. Moreover, a three-month reporting delay meant that, say, touchy negotiations with members of Congress were not immediately revealed.

The White House should not backslide on transparency. In fact, if the Trump administration is to use the billionaire’s Mar-a-Lago retreat and Trump Tower as second and third White Houses, at considerable cost to the public, it should release logs of who visits there, too. Members of Congress, meanwhile, should raise their transparency game at least to match the Obama administration’s. Their constituents are entitled to know who is helping to write the law.