Several legal experts said Mr. Trump’s vow to fight every subpoena is a departure from how past presidents confronted congressional oversight investigations run by their adversaries. The White House and lawmakers have generally resolved fights over internal information about the executive branch through negotiation and accommodation — a practice that courts have repeatedly said they want to see.
By contrast, Mr. Trump’s scorched-earth strategy appears meant to prompt a lengthy fight for each subpoena, by giving the House a choice between seeing its subpoenas ignored or going to court to ask a judge to order the administration to comply with them. Such lawsuits would then prompt wrangling in the courts over whether Mr. Trump had the authority to block the subpoena.
While relatively few definitive judicial precedents exist about where the executive branch’s power to keep private internal information stops and Congress’s power to gain access to it begins, a few cases may be notable for the emerging fights, specialists said.
In a 1997 appeals court ruling involving internal White House documents the Clinton administration wanted to keep from Congress, a panel of judges ruled that the administration had waived its ability to claim executive privilege over certain files because it had permitted a personal lawyer for an executive branch official to see them. Personal lawyers for current and former Trump administration officials reviewed many documents involving their clients during the special counsel investigation.
In a 2008 district court ruling involving whether a former White House counsel to President George W. Bush, Harriet Miers, could be compelled to testify before Congress, a judge said she had to show up and decide whether to decline to answer potentially privileged questions one by one. That could suggest that Mr. McGahn must similarly appear before the House Judiciary Committee.
And in a 2016 district court ruling involving internal Justice Department documents the Obama administration wanted to keep secret from Congress, a judge ruled that executive privilege no longer protected materials that had been disclosed in an inspector general report. Because Mr. Barr made most of Mr. Mueller’s report public, that principle may limit Mr. Trump’s success in asserting the privilege to block Congress from receiving testimony and documents about events described in the report.