Several congressional Republicans expressed skepticism this week about whether it is proper for President Donald Trump to accept a $400 million luxury plane from Qatar, to be retrofitted into a new Air Force One. Many shared concerns that the aircraft might include listening devices.

Others said it would cost too much or that it would take too long to add all the protections an American president needs in the event of a crisis.

Sen. Rand Paul (R-Kentucky) wondered whether the United States’ ability to speak out against human rights abuses in Qatar would be “clouded.” Senate Majority Leader John Thune (R-South Dakota) assured reporters that “there will be plenty of scrutiny” if and when a deal happens. “Congress needs to play a role,” said Rep. Rob Wittman (R-Virginia), vice chair of the Armed Services Committee.

This is precisely what the Founding Fathers intended for the legislative branch to do in just such a situation. Ultimately, Congress should decide whether to appropriate the hundreds of millions of dollars to overhaul a presidential plane. And before this happens, both chambers should vote on whether to accept the plane.

The Constitution’s emoluments clause is crystal clear: No U.S. official can accept “any present, Emolument, Office, or Title, of any kind whatever, from any King, Prince, or foreign state.”

This was no abstract hypothetical.

In 1785, two American diplomats received gifts from European monarchs: Benjamin Franklin got a snuffbox adorned with diamonds from France’s Louis XVI, and John Jay received a horse from Spain’s King Charles III. Congress voted to let both men accept the gifts, because lawmakers didn’t want to offend the foreign potentates. These experiences were top of mind when the framers met in Philadelphia two years later to draft a Constitution to replace the Articles of Confederation.

Before Trump, presidents abided by the emoluments clause. President Martin Van Buren asked Congress what to do when, in 1839, the sultan of Morocco gave him two lions and, in 1840, when the sultan of Oman sent pearls and horses. “I deem it my duty to lay the proposition before Congress for such disposition as they may think fit to make of it,” Van Buren wrote.

The pearls went to the Smithsonian, the lions went to a zoo and the horses were sold.

As always, some Trump loyalists defended the president’s wish to accept the plane. Sen. Markwayne Mullin (R-Oklahoma) invoked the example of the Statue of Liberty. “That was a gift, too,” he said. Actually, Congress voted to accept this gift from France. President Ulysses S. Grant signed the joint resolution on his final day in office in 1877.

Trump’s team argues that Congress can be bypassed in this case, because current law allows Defense Secretary Pete Hegseth to accept “personal property” from foreign persons or governments “for use by the Department of Defense.” Qatar’s government describes this as merely a “transaction … between the two defense ministries.”

Attorney General Pam Bondi signed a memo saying that accepting the plane is “legally permissible” because no explicit conditions are attached, which means it’s not a bribe. (Bondi was a registered lobbyist for Qatar before she became America’s chief law enforcement officer, and was paid $115,000 a month for her services.)

But Trump himself has tacitly admitted that it’s basically a gift for him, not the Air Force. He plans to transfer the jet to his presidential library shortly before he leaves office. Who will pay for that?

If Trump winds up using this plane without a green light from Capitol Hill, he risks creating a flying symbol for the world that the U.S. presidency is for sale. This isn’t happening in a vacuum.

The Trump Organization announced a deal last month to build a luxury golf resort in Qatar.

Separately, next Thursday, Trump will invite the 25 largest holders of his crypto meme coin for a private reception and tour of the White House and then he will have dinner with the top 220 holders.

Qatar has more to gain from giving the plane than the United States has in taking it. During one of their 2016 debates, Trump ripped Hillary Clinton over the Clinton Foundation’s accepting a contribution from Qatar because of the way the country treats women and children.

In 2017, during his first term, Trump criticized Qatar as having “historically been a funder of terrorism at a very high level” when Saudi Arabia and four other countries in the region boycotted Qatar over its support for Islamists and its ties to Iran.

Trump has changed his tune, and Qatar is already getting a great return on the investment it is trying to make. Only Congress can stop this from happening.