“Unfortunately, Congress consistently brings the government to the edge of default before facing its responsibility. This brinkmanship threatens the holders of government bonds and those who rely on Social Security and veterans benefits. Interest rates would skyrocket, instability would occur in financial markets, and the federal deficit would soar. The United States has a special responsibility to itself and the world to meet its obligations.”

— President Ronald Reagan, Sept. 26, 1987

This is not Ronald Reagan’s Republican Party.

Neither is it the party of the Republican Revolution of ’94, the tea-party-infused GOP of 2010, nor even the Republican Party that surrendered to Donald Trump in 2016.

No, this new version of the GOP is at once so radical and so lacking in responsible leadership that it is plunging headlong and unified toward forcing default on the full faith and credit of the United States. Congressional Republicans are inviting economic calamity.

Reagan presided over 18 increases in the debt ceiling during his presidency. George W. Bush’s treasury secretary, Paul O’Neill, compared those who opposed raising the limit to “terrorists.” Former Republican House speaker John Boehner called it “insanity” to hold the debt limit hostage — and those who did it “crazies.”

There have been squabbles over the debt limit for decades, including some near misses, but the United States has never defaulted on the debt its two parties have jointly accumulated. Though crazies threatened default, grown-ups in the GOP — Bob Dole, Boehner, an earlier incarnation of Mitch McConnell — pulled them back from the abyss.

Until now. The crazies are in charge. McConnell, the Senate GOP leader, says flatly that he won’t vote to increase the debt ceiling, and he isn’t even negotiating. “That’s their problem,” he says of the Democrats. And Sen. Ted Cruz (R-Tex.) has threatened to filibuster any debt-ceiling increase, which means Democrats can’t avoid default unless 10 Republican senators agree.

If Republicans don’t budge, they would leave the U.S. economy hanging by a thread, potentially forcing Democrats to raise the ceiling by rewriting and passing a massive (and filibuster-immune) budget reconciliation package in a matter of days. It’s the legislative equivalent of passing a camel through the eye of a needle.

As The Post’s venerable congressional correspondent Paul Kane notes, Republicans have entirely invented this new standard that Democrats alone are responsible for increasing the limit: “Almost every time the debt ceiling has been lifted, it has been done in bipartisan fashion under the regular Senate order that requires at least 60 votes to end debate on the legislation.”

The hypocrisy is stunning. McConnell has voted to increase or suspend the debt limit 32 times, including thrice under Trump, who added $7.8 trillion to the debt, The Post’s Jeff Stein reported. About 97 percent of the current debt existed before Joe Biden’s presidency; McConnell and his GOP colleagues are refusing to finance the debt they already incurred because they object to other spending that has merely been proposed.

How did Republicans get to this sorry state?

It began with Newt Gingrich, who as House speaker in 1995 led his party to suspend the “Gephardt Rule,” which automatically increased the debt limit with each year’s budget. Gingrich threatened default if President Bill Clinton didn’t agree to spending cuts. “I don’t care if we have no executive offices and no bonds for 60 days,” he said. But ultimately, he settled for relatively minor concessions.

When Republicans regained power in the House in 2011, they repealed the Gephardt Rule for good, guaranteeing perpetual debt-limit brinkmanship. Boehner pleaded with Republicans to be “adults” and told them to “get your ass in line,” but his crazies refused to budge, and finally, on the cusp of default and after a downgrading of the U.S. debt rating, President Barack Obama agreed to Republicans’ spending cuts. McConnell concluded he enjoyed playing chicken with the nation’s credit. “It’s a hostage that’s worth ransoming,” he said then.

So Republicans held the debt limit hostage again in 2013. Then, newbie senator Cruz forced a government shutdown in a doomed attempt to get Obama to agree to a repeal of Obamacare. It was a political disaster for Republicans, and as the shuttered federal government approached a default deadline, Boehner ordered Republicans to surrender. The following year, only some last-minute arm twisting by McConnell thwarted another Cruz attempt to block yet another debt-limit increase.

“Nobody was proud of the fact that we had to keep voting to raise the ceiling,” Boehner later wrote in his memoir. “But not voting to raise the ceiling meant that government would stop running. The country wouldn’t be able to pay its bills and would risk going into default on the money we owed.”

Now, Boehner is long gone, and McConnell rivals Cruz in his reckless handling of default. With the government now teetering on the edge of default and shutdown, there is simply nobody left to stop Republican crazies from sabotaging Americans’ prosperity.