On Wednesday, Republicans on the House Judiciary Committee repeatedly accused Attorney General Merrick B. Garland of singling out former President Donald J. Trump for selective prosecution, slamming him for what they call a “two-tiered system” of justice.
Forty-eight hours later, the Justice Department indicted one of the most powerful Democrats in the Senate — Bob Menendez of New Jersey, the chairman of the Foreign Relations Committee — on bribery charges, making public a trove of evidence, including cash and gold bars stashed at his house.
The department’s aggressive pursuit of Mr. Menendez appeared to undercut claims that Mr. Trump is the victim of pervasive political bias that targets leaders on the right while shielding transgressors on the left.
The entanglement of electoral politics and law enforcement is becoming the norm, and the prosecution of a top Democrat up for re-election in 2024 has political as well as legal reverberations. And the indictment, brought by federal prosecutors in Manhattan with limited participation from the Justice Department’s national security division in Washington, comes at a politically opportune moment for the besieged department.
“This case really should silence any critic who wrongly suggests that D.O.J. is politicized under Garland,” said Anthony D. Coley, a former spokesman for the department. “This D.O.J. follows the facts — and isn’t influenced by partisan politics, political affiliation or wealth — anything but facts and law.”
Barbara Comstock, a former Republican congresswoman from Virginia, said recent indictments showed the department was functioning as it should. “The department goes where the facts lead them,” she wrote on X, formerly known as Twitter. “Trump, Hunter Biden, Menendez now. That’s how it’s supposed to work.”
But the indictment could cut the other way, playing into the Republican argument, used so effectively by Mr. Trump during the 2016 campaign, that Washington is a swamp lorded over by corrupt Democrats. Republican reaction to the news was initially muted, but the Republican National Committee and House Republicans took to social media in an attempt to link Mr. Menendez to President Biden and the Hunter Biden scandal.
Rules adopted by Senate Democrats require Mr. Menendez to immediately step aside as chairman of his committee, as he did when he was first indicted in 2015, reclaiming his post when the charges against him were dropped three years later.
If that buys Democrats some breathing space, it does little to weaken the longer-term political challenges, with President Biden and Senator Charles Schumer, the majority leader, likely to face increasing pressure to urge a defiant Mr. Menendez to voluntarily resign his seat.
“Active matter, not going to comment,” said the White House press secretary Karine Jean-Pierre, when asked whether the president wanted the senator to quit.
Gov. Philip D. Murphy of New Jersey, who would have the power to appoint Mr. Menendez’s successor, called on Mr. Menendez to resign on Friday. His message was soon followed by like-minded calls from political leaders throughout the state.
Earlier in the day, several other Democrats made similar statements. Representative Dean Phillips of Minnesota compared the senator with Representative George Santos, the Long Island Republican indicted in May on 13 charges, including wire fraud. “It’s appalling,” Mr. Phillips told CNN.
But Mr. Menendez showed no sign of backing down. Some top Democrats, including Mr. Schumer and Senator Benjamin L. Cardin of Maryland, who is likely to take over his gavel on the committee, released statements urging patience while the judicial process played out.
Shortly after the charges were announced, Mr. Menendez issued a blistering one-page-long denial that was not unlike the vehement pushback by Mr. Trump and his supporters in response to his multiple criminal indictments.
“For years, forces behind the scenes have repeatedly attempted to silence my voice and dig my political grave,” he wrote. “The excesses of these prosecutors is apparent.”
Mr. Trump has not been accused of bribery or pay-to-play corruption. Yet Mr. Menendez’s indictment carries faint echoes of the investigation into the former president’s retention of classified documents at his Florida estate — most notably the inclusion of photographs from the senator’s house that were instantly disseminated on social media.
But the charges against Mr. Menendez, whose opposition to the administration’s efforts to thaw relations with Cuba rankled many in the White House, are highly unlikely to influence the Republican strategy of undermining public confidence in the Justice Department under Mr. Garland and federal law enforcement more generally.
During the contentious oversight hearing on Wednesday that foreshadowed the looming impeachment inquiry of President Biden, Republicans blasted Mr. Garland, time and again, for slow-walking the investigation into Hunter Biden, the president’s son, while fast-tracking two indictments against Mr. Trump.
“There’s one investigation protecting President Biden — there’s another one attacking President Trump,” said Jim Jordan, Republican of Ohio and chairman of the House Judiciary Committee. “The Justice Department’s got both sides of the equation covered.”
The hearing, which lasted more than five hours, focused primarily on the department’s five-year investigation of Hunter Biden, and a plea deal negotiated by David C. Weiss, the U.S. attorney for Delaware overseeing the case, that would have spared Mr. Biden prison time on gun and tax charges. That agreement fell apart during a court hearing in July, and the government has indicted Mr. Biden on three felony weapons charges, while continuing its investigation into his lucrative consulting deals with foreign companies.
The claim that Mr. Garland has weaponized the Justice Department for political purposes, while thus far unsupported by evidence, is a pillar of Republican messaging. Not only is it a way to rally the party’s base, but it is meant to counter a mountain of witness testimony and documentary evidence against Mr. Trump, who is accused of illegally retaining classified documents and trying to overturn the 2020 election.
“Our job is not to take orders from the president, from Congress, or from anyone else, about who or what to criminally investigate,” the attorney general said. “I am not the president’s lawyer. I will also add that I am not Congress’s prosecutor. The Justice Department works for the American people.”