A bitterly polarised reaction to an FBI search of Donald Trump's Mar-a-Lago home on Monday threatened to enflame America's political divisions.
The former president said agents "raided" his Florida resort and broke into his safe, a stunning turn of events apparently linked to a justice department investigation of his removal of official presidential records.
For Democrats and other Trump critics, it was a long overdue step towards justice and proof that no one - even a former president - is legally untouchable.
Congressman Eric Swalwell tweeted: "We are witnessing the difference between an honest system and a corrupt one. In 2020 Donald Trump brought us dangerously close to a permanently corrupt America. The rule of law is taking shape. And accountability is coming."
Ted Lieu, another Democrat in the House of Representatives, posted on Twitter: "No one is above the law."
And the Lincoln Project, an anti-Trump group, said in a statement: "Never before has a former President's home been raided in a criminal probe. While this search warrant is seemingly for the mishandling of classified material, it is a serious crime that must be fully investigated.
"Today's raid is the first step for law enforcement, or Congress, of holding Donald Trump accountable for the orchestration of a conspiracy to remain in power that resulted in the January 6th attack on our nation's capital."
But Republicans responded furiously to the development, following Trump's lead in claiming that the search showed the justice department waging a politically motivated witch-hunt. Their florid rhetoric will do little to assuage fears that a prosecution of Trump could lead to social unrest and even political violence.
Ronna McDaniel, chairwoman of the Republican National Committee, said: "Absolute power corrupts absolutely. Countless times we have examples of Democrats flouting the law and abusing power with no recourse.
"Democrats continually weaponize the bureaucracy against Republicans. This raid is outrageous. This abuse of power must stop and the only way to do that is to elect Republicans in November."
Kevin McCarthy, the Republican minority leader in the House, claimed in a statement that the justice department had reached "an intolerable state of weaponized politicization" and vowed that, when Republicans take back the House, they will conduct immediate oversight of the department.
He said ominously: "Attorney General Garland: preserve your documents and clear your calendar."
Lindsey Graham, a US senator for South Carolina and Trump ally, noted that midterm elections are about a hundred days away and Trump is likely to run for president again in 2024. "Time will tell regarding this most recent investigation. However, launching such an investigation of a former President this close to an election is beyond problematic."
Bob Good, a Republican congressman, wrote on Twitter: "The continued weaponization of the federal government against its citizens and political opponents continues under the Biden/Garland march toward a police state."
Congressman Ronny Jackson added: "Tonight the FBI officially became the enemy of the people!!!"
Kristi Noem, the governor of South Dakota, denounced the search as "un-American", while Matt Schlapp, chairman of the Conservative Political Action Conference (CPAC) - which hosted an event in Dallas, Texas, last week with speakers including Trump and Hungarian prime minister Viktor Orbán - also joined the condemnation.
"The Deep State will do anything in its power to slime President Trump," Schlapp said. "Americans need to keep growing the big Red Wave and save the country from these corrupt fascists."
Mike Pompeo, a former secretary of state under Trump, tweeted: "Executing a warrant against ex-POTUS is dangerous. The apparent political weaponization of DOJ/FBI is shameful. AG must explain why 250 yrs of practice was upended w/ this raid."
Biden has repeatedly stressed his belief that the justice department must work independently of the White House and that he will not interfere in its investigations. Merrick Garland, the attorney general, insisted last week that no one is above the law.
The FBI is directed by Christopher Wray, a Trump appointee.
The Republican response on Monday drew from a familiar playbook: Trump has long maintained that the Russia investigation, for example, was a "hoax" and part of a "deep state" conspiracy against him. Scrutiny of his removal of presidential records, or his role in the January 6 insurrection, is likely to produce a similar backlash.
Joe Walsh, a Trump critic and former Republican congressman, tweeted: "The Republican Party has abandoned the rule of law. Just listen to them tonight. They're at war with the rule of law.
David Axelrod, ex-strategist under Barack Obama, added: "This is why Trump is going to run. He wants to portray any criminal probe or prosecution as a plot to prevent him from once again becoming POTUS. Many of his followers will believe it - as they did his lies about the LAST election."