WASHINGTON -- Protesters from coast to coast called on President Trump over the weekend to release his tax returns.

He responded on Twitter, saying: “The election is over!... Now tax returns are brought up again?”

Someone should look into who paid for the small organized rallies yesterday. The election is over! — Donald J. Trump (@realDonaldTrump) April 16, 2017

Mr. Trump says he can’t release them because he’s under audit. But tax experts say that shouldn’t matter.

“The only one that cares about my tax returns are the reporters, okay?” Mr. Trump said in January.

But in February, a CBS News poll found that 56 percent of Americans think it’s necessary for him to release his tax returns. Forty-three percent said it’s not.

He is the only president not to release them in more than 40 years.

Before taking office, Mr. Trump often criticized President Obama for being too secretive. In 2012, he tweeted: “He is the least transparent President--ever--and he ran on transparency.”

Why is @BarackObama spending millions to try and hide his records? He is the least transparent President--ever--and he ran on transparency. — Donald J. Trump (@realDonaldTrump) June 6, 2012

But on Friday, the White House said its visitor logs will no longer be made public, a practice that President Obama started.

“Donald Trump’s White House is less transparent than Barack Obama’s White House,” said Kathleen Clark, a law professor and expert on government ethics.

“We do not know how much money the president owes and to whom he owes it,” she said.

Kathleen Clark CBS News

During the daily White House briefing on Monday, CBS News asked White House press secretary Sean Spicer about views on transparency.

“There are now ethics experts on both sides of the aisle who say this is the least transparent administration in decades. How do you respond?” CBS News asked.

“Well, I think that we’ve taken several steps to allow people’s access to this White House,” Spicer replied.

“We bring people in, we release participant lists, we give press the opportunity to come into the room, so I would respectfully disagree with that,” he said.

The Trump White House is even secretive about golf. Mr. Trump has visited golf courses 19 times as president, but in most of those cases the White House has refused to confirm or deny that he was actually golfing.