Democratic and Republican members of Congress alike on Sunday reproached President Biden over the discovery of yet another tranche of classified documents at his home in Delaware.

Why it matters: Democrats' increasing willingness to publicly rebuke the president signals the White House's allies are treating the gradual trickle of classified document revelations as a serious scandal.

• Saturday's announcement that the DOJ found more documents at Biden's home is the third such disclosure by the president's team this month.

What they're saying: "I'm concerned. There's a standard that we follow when it comes to members of Congress and classified information," said Sen. Dick Durbin (D-Ill.), the chair of the Senate Judiciary Committee, on CNN's "State of the Union." "To think any of them ended up in boxes in storage ... is just unacceptable."

• Sen. Joe Manchin (D-W.Va.), on NBC's "Meet the Press," said "to put those in unsecured spaces is irresponsible," and — in a rejoinder to Biden saying he has "no regrets" about his handling of the situation — said the president "should have a lot of regrets."
• He added on CNN: "It's unbelievable how this could happen. It's totally irresponsible."
• Sen. Tim Kaine (D-Va.), like his colleagues, contrasted Biden's handling of the documents with Congress' procedures for such materials on CBS' "Face the Nation": "It's always in a classified facility where I don't have access to the materials other than to sit there and read them."

Between the lines: Durbin acknowledged Biden lost the high ground on classified information: "Let's be honest about it, when that information is found, it diminishes the stature of any person in possession of them, because it's not supposed to happen."

• “The political fallout is it’s going to take focus and attention” away from Biden’s other priorities, Sen. Chris Coons (D-Del.) said on ABC’s "This Week."

Yes, but: Some Democrats rushed to Biden's defense, noting that the DOJ's search of his home on Friday was consensual and that Biden's team has not appeared to put up roadblocks to the investigation.

• Both Durbin and Coons pointed to the "sharp contrast" between Biden and former President Trump in terms of cooperating with the DOJ.
• "The important point there ... is that he had no idea," Coons said, "If you’re serving in the Senate or as vice president, you literally get millions of documents coming through your office. ... So, I do think this was inadvertent."
• Rep. Josh Gottheimer (D-N.J.), on "Fox News Sunday," said the White House has "cooperated in a constructive way," but added, "We need to get to the bottom of what happened."

The backdrop: Attorney General Merrick Garland has appointed former U.S. attorney Robert Hur as a special counsel to investigate the matter.

The other side: Republican lawmakers signaled that they see the classified documents as potentially developing into one of the landmark scandals of Biden's term.

• "Watergate started as a very small burglary and it led to the president of the United States resigning," said Rep. Michael McCaul (R-Texas), chair of the House Foreign Affairs Committee, on "This Week."
• Rep. Mike Turner (R-Ohio), chair of the Intelligence Committee, labeled Biden a "serial classified document hoarder" on “Face the Nation” and said of the White House's process of disclosing document discoveries: "This looks more like a cover-up than an investigation."
• Rep. Nancy Mace (R-S.C.), on “Meet the Press,” suggested Biden's document scandal is more severe than Trump's because, in Biden's case, "these documents were hidden for five years."