The White House on Sunday decried Democratic-led congressional investigations, saying Democrats are refusing to abide by "rules and norms" that govern oversight authority as they issue subpoenas for documents the Trump administration refuses to hand over.
"There are rules and norms governing congressional oversight of the executive branch, and the Democrats simply refuse to abide by them," White House deputy press secretary Steve Groves said in a statement. "Democrats are demanding documents they know they have no legal right to see -- including confidential communications between the President and foreign leaders and grand jury information that cannot be disclosed under the law."
The White House, Groves said, "will not and cannot comply" with what he called "unlawful demands made by increasingly unhinged and politically-motivated Democrats."
President Donald Trump responded later Sunday to Democrats' accusations of a constitutional crisis.
"The Democrats (sic) new and pathetically untrue sound bite is that we are in a 'Constitutional Crisis,'" Trump tweeted, calling them "a sad JOKE!"
He touted the economy, unemployment rates, "lower taxes & regulations," a "rebuilt" military spending and new judges.
"But we have had a giant SCAM perpetrated upon our nation, a Witch Hunt, a Treasonous Hoax," Trump wrote. "That is the Constitutional Crisis & hopefully guilty people will pay!"
The bevy of comments from the White House comes as Democrats become increasingly frustrated by what party leadership sees as unprecedented, across-the-board stonewalling of their oversight powers -- and various congressional investigations -- by the Trump White House.
Last week, President Donald Trump invoked blanket executive privilege over special counsel Robert Mueller's full report, preventing the House Judiciary Committee -- which had previously subpoenaed the Justice Department for a full, underacted version of the report -- from obtaining it.
Earlier Sunday, House Intelligence Chairman Adam Schiff criticized the President's move, saying on ABC's "This Week" that there's no basis for Trump using executive privilege to keep Democrats from obtaining the full report.
"But here, the Trump administration has decided to say a blanket no; no to any kind of oversight whatsoever, no witnesses, no documents, no nothing, claiming executive privilege over things that it knows there is no basis for," he said. "There's no executive privilege over the hundreds of thousands of documents regarding events that took place before Donald Trump was President."
"You can't have a privilege -- an executive privilege -- when you're not the executive," Schiff, a California Democrat, said.
In a Sunday tweet, Trump also took aim at a separate subpoena issued last week to his son, Donald Trump Jr., calling the move by the Republican-controlled Senate Intelligence Committee "Really sad!"
In response to the subpoena, Trump Jr., who does not work in the administration, is considering two options: invoking his fifth amendment rights or not appearing at all, a source told CNN last week.