Republicans walked out of debt-limit negotiations Friday, charging Democrats with being “unreasonable” in the face of the GOP’s threat to crash the global economy.

This renewed calls from some Democrats for President Biden to invoke the 14th Amendment as a way of doing an end-run around Republicans’ brinkmanship.

What is that? And would it work? Let’s take a look.

Section 4 of the 14th Amendment says: “The validity of the public debt of the United States, authorized by law, including debts incurred for payment of pensions and bounties for services in suppressing insurrection or rebellion, shall not be questioned.”

Some, including constitutional scholar Laurence Tribe, say this provision empowers the president to take charge of debt management.

“This is a guarantee that the U.S. will always be good for all its debts, period,” Tribe says.

The U.S. Chamber of Commerce countered that using the 14th Amendment in this fashion “would be as economically calamitous as a default triggered by a failure to lift the debt limit in a timely manner.”

The differing viewpoints reflect the fact that the amendment has never been tested for this purpose.

The 14th Amendment dates back 145 years and was part of changes to the Constitution that bestowed citizenship on former slaves.

But the wording of Section 4 raises the tantalizing possibility that a president can take charge of debt management to safeguard “the validity of the public debt.”

The importance of such oversight, it says emphatically, “shall not be questioned.”

In effect, the amendment makes clear that, like the Lannisters in “Game of Thrones,” the United States always pays its debts.

The fact that the amendment has never been used to raise the debt limit demonstrates that this is unproven legal ground. Past administrations have considered trying it, but each time decided the move was too risky.

Would it represent an abuse of executive power by circumventing Congress? Would it make the debt limit meaningless despite the will of Congress?

Biden has indicated he’d rather not go down this road and spark a new round of legal skirmishing with Republicans that would inevitably make its way to the Supreme Court.

Still, it’s intriguing to consider that the Constitution clearly says “the validity of the public debt” shall not be questioned.

At the moment, Republicans are doing just that.