President Trump has entertained some high-profile visitors at his oceanside resort Mar-a-Lago.

Japanese Prime Minister Shinzo Abe dined and golfed there in February, when the two leaders hashed out strategy for how to respond to a missile launch by North Korea. And in April, Trump welcomed Chinese President Xi Jinping to Mar-a-Lago for a two-day summit.

But little is known about who else the president has hosted at the lavish estate in Palm Beach, Fla., which he has called his winter White House, or at his other residences. The administration has turned down requests from government watchdog groups and others for the release of visitor records under the Freedom of Information Act.

That may soon change.

On Monday, a nonprofit watchdog called Citizens for Responsibility and Ethics in Washington, or CREW, announced that the Department of Homeland Security agreed to turn over logs for Mar-a-Lago in a response to a lawsuit the group filed with the National Security Archive and the Knight First Amendment Institute at Columbia University . CREW plans to release the information publicly by Sept. 8.

“It’s important for the American people to know who has access to the president and his advisors and who is potentially influencing policy,” said Noah Bookbinder, the group’s executive director.

The three watchdog groups also sued for access to visitor records for the White House and for Trump Tower in New York, but it is unclear whether they will get them.

Homeland Security says it does not have such records for Trump Tower. And the White House announced in April that it would keep its logs secret, citing “grave national security risks” as well as “privacy concerns of the hundreds of thousands of visitors annually.”

Advocates for open government accuse Trump of reneging on his campaign promise to “drain the swamp” in Washington. But his administration is not alone in seeking to keep its meetings private.

The Obama White House turned down multiple requests to view its visitor logs before agreeing in 2009 to post most of the names online after it too was sued by CREW.

Why do watchdog groups want to see these logs?

Transparency advocates say the logs are an important tool for monitoring which individuals and organizations may be trying to influence White House policy.

“Most people can’t get a meeting with the president,” Bookbinder said. “Who the White House staff and the president are meeting with says a lot about what their priorities are. It may well influence their ultimate decisions, and that information is really helpful for understanding how policy is being made.”

The president’s use of a private club to carry out government business also raises potential ethical questions. Citizens for Responsibility and Ethics in Washington would like to know whether Mar-a-Lago members, who it says are in effect paying customers of the president, may be getting access to him in ways that other people do not.

Are there legitimate reasons not to release them?

Government officials may want to keep some meetings private for national security or law enforcement reasons. They may also worry that some people won’t meet with them — or may provide less than candid advice — if they think their presence in the White House might become public knowledge.

But public policy experts argue that such concerns must be weighed against the public’s right to know how decisions are made. Who is the president taking advice from? Is he getting a balance of viewpoints on crucial policy issues? Are any groups exerting undue influence?

“Those are all very serious questions,” said Mark J. Rozell, dean of the Schar School of Policy and Government at George Mason University .

“Presidents and their advisors may feel they get better quality advice if they can protect the identities of people who would rather not be publicly disclosed, but I think as a matter of principle, it’s the right thing to do,” Rozell said. “We’re a democratic system based on the principal of accountability. And how can you hold leading officials accountable if we don’t know even who they are talking to and how they are developing policy ideas?”

How can you hold leading officials accountable if we don’t know even who they are talking to and how they are developing policy ideas? — Mark J. Rozell, dean of the Schar School of Policy and Government at George Mason University

President Trump, left, hosted Chinese President Xi Jinping, right, for a two-day summit at his Mar-a-Lago resort in April. (Alex Brandon / Associated Press)

How does Trump compare with his Republican and Democratic predecessors?

“There is an institutional pattern across both political parties,” Rozell said. “When they get to the White House, they might talk about openness and transparency, but increasingly they all begin to shut down access as much as possible and to protect sources of information.”

Trump’s relationship with the media may be more fraught than most. Under his watch, cameras have been banned from news conferences and prominent journalists barred from covering his events. But other administrations have also resisted disclosing information about their internal workings.

President Clinton, whose relationship with Monica Lewinsky lead to impeachment charges, didn’t want to provide records showing how many times she visited the White House in the months after her internship ended.

President George W. Bush resisted releasing records about the industry executives who advised an energy task force led by Vice President Dick Cheney .

President Obama, who campaigned on a promise to lead the most open administration in history, initially fought attempts by Congress and watchdog groups to obtain White House visitor records. But he relented to settle four lawsuits filed by CREW.

In December 2009, officials began posting records every three to four months with the names of those who had been at the White House, the dates and times of their visits, and the names of the people they had met. However, the administration did not provide information about who the visitors were or the reasons for their visits, which limited the utility of the lists.

“If somebody named Michael Jordan visited the White House, is it the basketball player or is it the lobbyist?” Rozell said. “It’s a fairly common name. There was no way to tell.”

The administration also left some names off the list, including personal guests of the Obama family and those who had come for “particularly sensitive meetings,” such as candidates for a Supreme Court nomination.

Still, millions of records were ultimately released. Groups such as CREW hoped that might serve as a precedent for future administrations.

So far, however, Homeland Security has agreed to disclose Secret Service records for visitors to Mar-a-Lago only through March 8, the period covered by CREW’s initial Freedom of Information Act request.

Records of White House visits remain under litigation.

Is this a political witch hunt?

Since Citizens for Responsibility and Ethics in Washington was founded in 2003, it has repeatedly been accused of being a left-wing “attack dog” masquerading as a nonpartisan watchdog.

The group was formed in part as a counterbalance to more conservative legal advocacy organizations such as Judicial Watch.

At the time, Republicans controlled the White House and both houses of Congress, and CREW’s founders saw a need for more aggressive efforts to expose the influence of money on politics and hold public officials accountable, Bookbinder said. But he maintains that the group has been just as vigilant when Democrats were in charge

“We sued the Bush administration. We sued the Obama administration. We sued the Trump administration,” he said. “We really treated everyone the same on this one.”