Top House Republicans intensified their attacks on President Biden and the Justice Department on Friday after the federal indictment of former President Donald J. Trump, suggesting falsely that Mr. Biden, not a grand jury made up of American citizens, had charged him with crimes as part of a political vendetta.
It was the latest instance of top-ranking Republicans in Congress closing ranks behind the former president and helping to spread unfounded accusations against the government, in the process undermining public confidence in the rule of law and stoking intense anger in their party’s base against the nation’s institutions.
“Let’s be clear about what’s happening: Joe Biden is weaponizing his Department of Justice against his own political rival,” said Representative Steve Scalise, of Louisiana, the No. 2 House Republican. “This sham indictment is the continuation of the endless political persecution of Donald Trump.”
Mr. Scalise’s comments followed those of Speaker Kevin McCarthy, who vowed to “hold this brazen weaponization of power accountable.”
“It is unconscionable for a President to indict the leading candidate opposing him,” Mr. McCarthy wrote on Twitter on Thursday evening, adding, “I, and every American who believes in the rule of law, stand with President Trump against this grave injustice.”
The Justice Department has gone to some lengths to put distance between the White House and its work, appointing two special counsels to review both Mr. Trump’s and Mr. Biden’s handling of classified documents in an attempt to insulate the investigations from allegations of political influence. White House officials said Mr. Biden learned of the charges against Mr. Trump at the same time as the rest of the public.
But House Republican leaders have closely aligned themselves with Mr. Trump for years, and are under more intense pressure than ever from their right flank to defend him as they struggle to hold together a governing majority in the House.
Representative Elise Stefanik of New York, the No. 3 G.O.P. leader, suggested that the charges, which were brought by a special counsel who for months has examined Mr. Trump’s handling of classified documents, were timed to distract from House Republicans’ investigation into Mr. Biden’s family.
“The exact same day that the F.B.I. is forced to turn over to Congress absolutely damning and credible allegations regarding Joe Biden’s illegal, egregious, and treasonous corruption, Joe Biden weaponizes his Department of Justice to indict Donald Trump,” Ms. Stefanik said on Friday.
She was referring to a document that contains an unsubstantiated, years-old allegation of bribery against Mr. Biden that was examined and deemed unworthy of further investigation by Mr. Trump’s Justice Department.
House Republicans have reacted with outrage since the charges were made known on Thursday night, vowing to use their majority in Congress to fight the Justice Department.
“WITCH HUNT,” was posted on the Twitter account of the Republican-led House Judiciary Committee within minutes of news of the indictment becoming public.
The chairman of that panel, Representative Jim Jordan of Ohio, has used his perch to attempt to pressure the Justice Department over what he views as unfair treatment of Mr. Trump. Mr. Jordan this week sent a letter to Attorney General Merrick Garland demanding unredacted documents concerning the investigation of the special counsel, Jack Smith.
Members of Congress have no power to stop criminal charges, but they can attempt to interfere with prosecutors through their legislative powers, such as issuing subpoenas, demanding witness interviews or documents, restricting Justice Department funding and using the platform of their offices to attempt to publicly influence the case.
They can also set the tone for how their constituents regard the prosecution of the former president and current Republican presidential nominee, an unprecedented phenomenon in American history.
One member of Congress, Representative Clay Higgins, Republican of Louisiana, hinted at a major backlash, in a cryptic tweet that appeared to refer to Mr. Trump as the true American president — “rPOTUS,” an acronym sometimes used by his supporters for “real president of the United States” — referenced the scale used in military maps, and told his followers to “buckle up.”
Senate G.O.P. leaders have struck a different tone, with the top two Senate Republicans remaining silent after the indictment.
Senator Mitt Romney of Utah, his party’s former nominee for president and a leading critic of Mr. Trump, condemned the former president’s conduct.
“Mr. Trump brought these charges upon himself by not only taking classified documents, but by refusing to simply return them when given numerous opportunities to do so,” Mr. Romney said in a statement.