President Trump, with a well-known fondness for golf hats bearing slogans, toured post-Hurricane Houston on Tuesday wearing white headgear emblazoned with "USA." It had a U.S. flag on one side, and on the other side — maybe this was the giveaway — the numeral 45. Trump is the 45th president.

It was merchandise from his re-election campaign's online store. On a webpage not updated since January, the campaign sells "the Official USA rope hat worn by 45th President-Elect Donald J. Trump, himself" for $40 – available in red, camouflage or white. And yes, it was made in the U.S.A., according to the website.

The White House issued a press release with photos of the white-hatted president meeting with Texas Gov. Greg Abbott and other officials. A White House spokeswoman seemed to dismiss concerns about merchandising, citing the hat's USA logo.

But Fred Wertheimer of the watchdog group Democracy 21 said Trump has blended his business activities with his White House duties.

"There's no apparent line for the president on how his office can be used for financial benefit, for profit going into his pocket or money going into his campaign," Wertheimer said. "In essence, he's now licensing the presidency."

The Trump re-election campaign, not Trump himself, profits from sales of campaign merchandise. During the 2016 campaign, Trump regularly appeared at rallies wearing a "Make America Great Again" cap, which his campaign committee still sells for $25. Trump also owns the "Make America Great Again" trademark.

No other president has created a re-election campaign committee as quickly as Trump.

Another watchdog group, Citizens for Responsibility and Ethics in Washington, found fault with the official photos. Spokesman Jordan Libowitz said, "The White House should be dedicated to the people's business, not Trump's business. It is wholly inappropriate for them to promote Trump products, of any kind, at any time."

CREW is already suing Trump for alleged violations of the Constitution's Foreign Emoluments Clause. The lawsuit says Trump profits from lavish spending by foreign diplomats at his hotel near the White House.

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