WASHINGTON - When Speaker Kevin McCarthy suggested recently he might stop the FBI from relocating its downtown headquarters to a new facility planned for the Washington suburbs, it was more than idle thinking about an office renovation.

The nod from the Republican speaker is elevating a once-fringe proposal to upend the FBI in the aftermath of the federal indictment of Donald Trump over classified documents and the Justice Department’s prosecution of his allies, including some of the nearly 1,000 people charged in the Jan. 6, 2021 attack on the Capitol.

Moving from far-right corners into the mainstream, the emerging effort to overhaul the nation’s premier law enforcement agency is rooted in increasingly forceful conservative complaints about an overly biased FBI that they claim is being weaponized against them.

“This is a pretty dramatic reversal of what the politics would have been 50 years ago,” said Beverly Gage, a historian at Yale who won a 2023 Pulitzer Prize for her biography of the legendary FBI director, “G-Man: J. Edgar Hoover and the Making of the American Century.”

The shifting attitudes among Republican members of Congress toward the FBI underscore the way Trump’s personal grievances have become legislative policy. Once the party of law and order, Republicans are now antagonists of federal law enforcement, undermining a storied institution and attacking Justice Department officials whose work is foundational to American democracy.

While political criticism of the FBI has followed the bureau since its founding with Hoover, who famously wiretapped civil rights leaders and orchestrated the infiltration of left-wing political organizations, the right-flank campaign against federal law enforcement had mostly simmered at the margins of party politics.

But the Justice Department’s indictment of Trump, who has pleaded not guilty to 37 felony counts over storing and refusing to return classified documents at his Mar-a-Lago club, and the ongoing prosecution of Trump supporters who stormed the Capitol, have fueled conservative anger. The Justice Department is also investigating Trump and his allies over the effort to challenge President Joe Biden’s election in the run-up to the 2021 Capitol attack.

Conservatives criticize the federal law enforcement on multiple fronts; among them, its work with social media companies to flag potentially dangerous postings, and a COVID-era memo from Attorney General Merrick Garland directing resources to combat violence against school officials. They compare the Trump investigations with what they say was a sweetheart deal for Hunter Biden, the president’s son, who is pleading guilty to misdemeanor tax evasion after a long investigation.

“Looking at the actions of the FBI, I think the whole leadership needs to change,” McCarthy told reporters at the Capitol last month.

Fresh from a visit with law enforcement in California, McCarthy said he envisions decentralizing the FBI by spreading operations into the states.

“This idea that we’re going to build a new, big Pentagon and put all the FBI mainly in one place, I don’t think it’s a good structure,” McCarthy said Friday, panning a conservative-led proposal to relocate the FBI to Alabama.

“I’d like to see the structure of a much smaller FBI administration building, and more FBI agents out across the country, helping to keep the country safe,” he said.

In many ways, the resistance to a robust federal law enforcement agency extends a thread that has run across American history - from the aftermath of the Civil War, when Southern states rejected federal troops for Reconstruction, to Trump’s own 2024 campaign announcement in Waco, Texas, a region known for the federal siege of a separatist compound in 1993.