California Rep. Adam Schiff said "it's a sober moment for the country," telling Linsey Davis on ABC News Live on Thursday that the dignity of the Oval Office "will be tarnished by the conduct of the former president by his being charged criminally."

"I think you have to be guided by the facts and the law, and you have to set aside the political calendar and do what the law requires," said Schiff, a leading Democrat in the House. "I think that's the obligation of a district attorney, and I think that was done here. How this cuts politically, I really don't know. That, to me, is very secondary."

-ABC News' Imtiyaz Delawala and Anna Katharine Ping

Demonstrators gathered outside Manhattan Criminal Court and near Donald Trump's Mar-a-Lago estate in Florida in the wake of the indictment Thursday evening.

In Manhattan, a giant sign that stated "Trump lies all the time" could be seen unfurled outside Manhattan Criminal Court, where police had erected barricades last week ahead of a possible indictment.

Meanwhile, several supporters gathered near Mar-a-Lago with Trump 2024 flags and signs.

Senate Majority Leader Chuck Schumer urged "Trump’s critics and supporters to let the process proceed peacefully and according to the law" in a statement following the indictment of the former president.

"Mr. Trump is subject to the same laws as every American," Schumer said. "He will be able to avail himself of the legal system and a jury, not politics, to determine his fate according to the facts and the law."

Lawmakers on both sides of the aisle took to Twitter to react to the historic indictment on Thursday evening, laying bare the sharp partisan divide when it comes to Donald Trump.

GOP House and Senate members decried the investigation by the Manhattan district attorney as a political prosecution.

Many Democrats, on the other hand, praised the decision as proof "no one is above the law."

Read more here.

-ABC News' Alexandra Hutzler

Manhattan District Attorney Alvin Bragg on Friday again resisted the House GOP investigation of his office’s prosecution of Trump.

Bragg’s legal counsel called the inquiry “illegitimate incursion” into a legitimate investigation.

The House Republicans -- Reps. Jim Jordan, James Comer and Bryan Steil -- have said they want to find evidence of federal funds used to investigate Trump. But Bragg’s office said they were merely doing Trump’s bidding.

“Finally, as you are no doubt aware, former President Trump has directed harsh invective against District Attorney Bragg and threatened on social media that his arrest or indictment in New York may unleash 'death & destruction.' As Committee Chairmen, you could use the stature of your office to denounce these attacks and urge respect for the fairness of our justice system and for the work of the impartial grand jury," counsel Leslie Dubeck wrote in a letter to the lawmakers.

"Instead, you and many of your colleagues have chosen to collaborate with Mr. Trump’s efforts to vilify and denigrate the integrity of elected state prosecutors and trial judges and made unfounded allegations that the Office’s investigation, conducted via an independent grand jury of average citizens serving New York State, is politically motivated.”