Officials in the Biden administration and its allies are scrambling to downplay the second downgrade of America’s debt in history, blaming the vote of no confidence from one of the world’s top rating agencies on President Trump and Republicans in Congress.

Overshadowed as it was by the third indictment of Mr. Trump, the downgrade from Fitch Ratings late Tuesday left Democrats both within and outside the administration pointing fingers and rushing to blame the messenger. The White House press secretary, Karine Jean-Pierre, said the downgrade “defies reality.” Secretary Yellen called it “arbitrary and based on outdated data.” An anonymous “senior Biden administration official” told Reuters that the decision was “bizarre and baseless.”

“It simply defies common sense to take this downgrade as a result of what was really a mess caused by the last administration and reckless actions by congressional Republicans,” the official reportedly added.

Fitch said the downgrade was warranted, in part, because of the lack of fiscal discipline and infighting in Congress over the debt ceiling and government spending. The constant political standoffs in Congress over the past 20 years, it said, has led to what it called an “erosion of governance.” A top official at the agency confirmed Wednesday that the events of January 6, 2021, contributed to its rationale.

“It was something that we highlighted because it just is a reflection of the deterioration in governance, it’s one of many,” a senior director at the company, Richard Francis, told Reuters.

Democrats in Congress jumped on the chance to publicly blame the GOP and Mr. Trump for the downgrade. In statements that ricocheted around Capitol Hill in the minutes and hours following the announcement, they said the GOP’s intransigence was to blame for the fact that two of the world’s three major rating agencies have now downgraded America’s long-term debt. That Fitch also said the country’s profligate spending in recent years was another reason for the downgrade went unsaid on that side of the aisle.

Senator Whitehouse said there was “a straight line from Republicans’ manufactured debt crisis to Fitch’s downgrade.” Senator Schumer said Republicans “need to learn from their mistakes and never push our country to the brink of default again.” A Pennsylvania Democrat in the House, Brendan Boyle, trotted out the familiar “extreme MAGA Republicans” trope to make his point.

While some economists sided with the White House in public comments Wednesday — a former Treasury secretary, Larry Summers, notably called the decision “bizarre and inept” — more fiscally hawkish observers noted that the nation’s $32 trillion debt is now well above its annual GDP and on a course that is unsustainable in even the short term.

With headlines warning of an “unprecedented” default on its debt during the most recent debt-ceiling fight, they asked, why wouldn’t Fitch warn investors that there is only a “very low level of default risk,” which is what the AA+ rating means, as opposed to the “lowest expectation” that America would renege on its financial obligations, which is what the AAA rating means?

Republicans in Congress were quick to point out that, despite the protests of the Biden administration and Democrats, the current occupant in the White House and his allies on the Hill have shown little inclination to curtail the spending that has put America in its current situation. They like to point out that Mr. Biden’s policies — from electric vehicle subsidies to support for Ukraine to trying to cancel student loan debt — have added some $11 trillion to the national ledger since he took office.

“You can’t burn through an unprecedented eleven trillion dollars igniting an inflationary firestorm without setting off the fiscal fire alarm,” the chairman of the House Budget Committee, Jodey Arrington, said in a statement released Tuesday night. “With annual deficits projected to double and interest costs expected to triple in just ten years, our nation’s financial health is rapidly deteriorating and our debt trajectory is completely unsustainable.”