WASHINGTON – Senior Democrats requested Thursday that special counsel Robert Mueller appear before Congress to testify on his investigation into Russian interference in the 2016 election.

"It is clear Congress and the American people must hear from Special Counsel Robert Mueller in person to better understand his findings," Jerrold Nadler, chairman of the House Judiciary Committee, wrote on Twitter following a press conference by Attorney General William Barr. Nadler requested Mueller appear no later than May 23.

Intelligence Committee Chairman Adam Schiff also "formally invited" Mueller to appear before his panel to discuss the investigation, sometime next month.

Mueller's long-awaited report came out Thursday morning.

Democrats have been in an uproar over Barr's decision to hold a press briefing prior to the public release of Mueller's report, saying it would have been better for him to take questions once the public and lawmakers have a chance to see the document for themselves.

Senate Minority Leader Chuck Schumer called Barr's press conference a "campaign press conference" for the president.

For weeks, House Democrats have criticized Barr's handling of the report but those critiques have intensified hours before the Justice Department is set to release a redacted version of the 400-page document to the public.

House Speaker Nancy Pelosi, D-Calif., and Schumer, D-N.Y., condemned what they said was "Barr’s regrettably partisan handling of the Mueller report."

"We believe the only way to begin restoring public trust in the handling of the Special Counsel’s investigation is for Special Counsel Mueller himself to provide public testimony in the House and Senate as soon as possible," the statement said. "The American people deserve to hear the truth.”

The House Democratic committee chairmen also voiced frustration with Barr.

"Once again, Barr wants to shape the public's perception of the report," House Intelligence Committee Chairman Adam Schiff, D-Calif., wrote on Twitter. "This is not justice. Just PR."

In a joint statement, Democratic House chairs called Barr's news conference "unnecessary and inappropriate" and called for release of the full report.

“These new actions by the Attorney General reinforce our concern that he is acting to protect President Trump," the statement said.

More:AG William Barr to hold news conference Thursday on before Mueller report goes to Congress

Nadler said the idea to release the report after Barr's news conference was ill-advised. "This is wrong," he wrote in a tweet. He continued, saying he was "deeply troubled" by the Times report about contact between the Justice Department and the White House before the report was released.

Nadler, D-N.Y., along with four House Democrats, held a last-minute news conference in New York Wednesday to discuss both Barr's delayed release of the report and his handling of the probe as a whole.

"The attorney general appears to be waging a media campaign on behalf of President Trump, the very subject of the investigation at the heart of the Mueller report," Nadler said. "Rather than letting the facts of the report speak for themselves, the attorney general has taken unprecedented steps to spin Mueller’s nearly two-year investigation."

Alongside Nadler was Rep. Hakeem Jeffries, D-N.Y., who tweeted that Barr's handling of the report equated to a "dog and pony show" and urged Barr to "keep your mouth shut."

"So-called Attorney General is presiding over a dog and pony show. Here is a thought. Release the Mueller report tomorrow morning and keep your mouth shut," Jeffries said. "You have ZERO credibility."

Rep. David Cicilline, D-R.I., also questioned Barr's intentions.

"Why is William Barr holding a press conference if not to (once again) try and frame the Special Counsel’s findings," he wrote on Twitter. "Just release the full report and let the American people judge for themselves!"

On Twitter, Rep. Doug Collins, R-Georgia, lashed out at Nadler while defending Barr's handling of the report.

"The only person trying to spin the report is @RepJerryNadler," Collins tweeted. "The AG has done nothing unilaterally. After partnering with DAG Rosenstein to share principal conclusions, Barr is releasing the report voluntarily, working with Mueller’s team step by step."

A Monmouth University poll released Wednesday found 60% of Americans want to see Congress get full access to the Mueller report, while only 30% said the Justice Department should be able to redact information deemed sensitive.

Still, a majority of Americans polled, 54%, said Congress should move on to other issues after the report's release. Just 39% said Congress should continue to look into topics related to the report.

“Most of the public wants Congress to see everything (Mueller) dug up, but not necessarily do anything about it. This seems to be tied to a pervading sense that they are unlikely to learn anything about the Trump circle that would be all that out of character with what we’ve come to expect,” said Patrick Murray, director of the Monmouth University Polling Institute.

Alice Stewart, a Republican strategist who worked on Sen. Ted Cruz's 2016 presidential campaign, predicted that Democrats would "light their hair on fire" over the redactions but said that would likely backfire politically.

"Critics of the president will look at any black spot on this report and jump to the absolute worst conclusion," she said.

She acknowledged the full report likely won't all be positive. However, she said Trump and the administration will be cleared and the country should move on.

"Certainly there will be things in the report that the administration would rather not be made public, but that doesn’t mean it's illegal or concerning moving forward," she said.

Tyler Law, a Democratic strategist who worked for the House Democrats' campaign arm during the 2018 election, said oversight was part of Congress' job and the party took back the House by promising to be a check on Trump.

Law said Democrats can both conduct oversight and deliver on issues voters care about.

"This is similar to the 2018 midterms. Democrats are remaining focused on the issues that we know are going to drive voters, health care and the economy. What people don’t want is a candidate who is focused exclusively on the president," he said.

Law dismissed the idea that Democrats could overplay their hand.

"People are not stupid. They understand that this is President Trump's scandal and every time it’s brought up it hurts him," he said.

Contributing: Bart Jansen, USA TODAY