The Senate Judiciary Committee voted along party lines Thursday to authorize subpoenas targeting more than 50 people involved in the decision to begin investigating President Trump’s 2016 campaign over potential links to Russia.

The subpoenas are part of a larger GOP effort to question the investigations into Trump, which culminated in the appointment of special counsel Robert S. Mueller III and consumed the early years of his presidency.

The Mueller report said investigators found insufficient evidence to show a conspiracy between the Trump campaign and Russia to influence the election and reached no conclusion about whether Trump obstructed justice — despite laying out episodes of the president apparently seeking to stymie the investigation.

Another Senate committee approved a similarly sweeping set of subpoenas last week, and a Justice Department prosecutor, John Durham, is investigating the origins of the probe at the behest of Attorney General William P. Barr.

Chairman Lindsey O. Graham (R-S.C.) signaled he is focused on multiple aspects of the federal investigation, which began in summer 2016 as an FBI counterintelligence probe deemed “Crossfire Hurricane” and continued into the early months of Trump’s presidency. Among them: The Justice Department’s reliance on a dossier compiled by a former British intelligence agent in seeking secret surveillance warrants and whether officials ignored red flags in continuing those warrants.

“Anybody that was told about the unreliability of the dossier and continued to use it, they’re good candidates to go to jail or lose their job,” Graham said, adding: “Somebody needs to be held accountable for what happened here, and we’re going to be in the accountability business.”

Republicans on the committee approved the subpoenas over the objections of Democrats, who denounced the investigation as both a partisan affair aimed at aiding Trump’s reelection campaign and a distraction from more pressing work for the committee — such as addressing the national crisis over racism in policing sparked by the killing of George Floyd in Minneapolis.

“The nation is demanding revolutionary change in our police practices to heighten justice and eliminate racism. It is a classic opportunity for this committee to lead,” said Sen. Richard Blumenthal (D-Conn.). “And if we devote our attention to this investigation . . . we are going to distract ourselves from that obligation and opportunity to really reform our criminal justice system.”

But Democrats launched a broader attack on the political implications of Graham’s probe. The subpoena targets dozens of officials, including several political appointees of former president Barack Obama — such as his attorney general, Loretta E. Lynch; his deputy attorney general, Sally Yates; his FBI director, James B. Comey; and his chief of staff, Denis McDonough.

Those subpoenas, they said, would do little more than offer fodder to Trump allies in the hothouse of his reelection campaign, while ignoring ample evidence of suspicious activity justifying the federal scrutiny that occurred.

Democratic senators seized on the case of former Trump national security adviser Michael Flynn, who twice pleaded guilty to lying to investigators about his conversations with the Russian ambassador. He later sought — with Trump’s support — to reverse that plea, and the Justice Department moved to drop the charged earlier this month.

The judge in that case, U.S. District Judge Emmet Sullivan in D.C., appointed a former federal prosecutor and judge to review the move to withdraw the Flynn charges. That appointee, John Gleeson, filed a scathing brief Wednesday identifying “clear evidence of a gross abuse of prosecutorial power” — a document that several Democrats referenced Thursday.

“Furthering Trump’s conspiracy theories is not the job of the Senate Judiciary Committee,” said Sen. Mazie Hirono (D-Hawaii).

Republicans voted to authorize the subpoenas after rejecting multiple Democratic amendments to Graham’s request. Many sought testimony from Trump-related figures, including Trump’s personal lawyer, Rudolph Giuliani, son-in-law Jared Kushner, and former lawyer Michael Cohen, as well as Flynn.

“This is stacked, my friends,” Sen. Richard J. Durbin (D-Ill.) said, calling for additional testimony from Cohen on Trump’s business ventures in Russia.

Rejecting the request, Graham said that was already the subject of multiple investigations, alluding to the probes done by Mueller, the congressional intelligence committees and others. “Now,” he said, “we’re going to look at how it got off the rails.”

Graham said at another point that he was “not going to be deterred” in completing his probe ahead of the election.

“It is clear to me I have to do this this way if I want to get to the bottom of what happened,” he said. “I promise you, you will have your say in an appropriate fashion. . . . But you’re trying to stop me from doing something I think the country needs to do. And I’m not going to be stopped.”

Over the nearly two-year investigation, Mueller charged 34 people, including 26 Russian nationals, and secured guilty pleas from seven, including several high-level Trump campaign and administration officials. The investigation concluded in March 2019 and the following month the Justice Department released the office’s report documenting its work.