The White House and the Justice Department repeatedly have cited executive privilege to defy the requests, in some cases prompting lawmakers to sue the administration in federal court. Executive privilege is the president's power to keep information from the courts, Congress and the public to protect the confidentiality of the Oval Office decision-making process. The privilege to withhold documents and prohibit aides from testifying rests on the proposition that the president has an almost unparalleled need to protect the confidentiality of candid advice that goes into presidential judgments.
The clashes involve everything from President Donald Trump's income tax returns to testimony from witnesses interviewed as part special counsel Robert Mueller's report on Russian interference in the 2016 presidential election.
Some examples: WHISTLEBLOWER Acting Director of National Intelligence Joseph Maguire, who testified to the House Intelligence Committee on Thursday, had withheld a whistleblower's complaint from Congress for weeks. He said Thursday that he did so because of executive privilege, adding that he lacked the authority to waive it. The complaint was released to Congress on Wednesday and to the public on Thursday just before the hearing.
__ TAX RETURNS Trump defied longstanding practice by presidential candidates when he refused to release his tax returns, claiming he's being audited by the Internal Revenue Service. The agency has said an audit wouldn't bar anyone from releasing their returns. The Democratic-led House Ways and Means Committee said it needs to see the returns as part of its investigation into tax law compliance by Trump, among other things. Treasury Secretary Steven Mnuchin refused to turn over the returns. The committee went to court in July.
__ WITNESSES The White House has invoked executive privilege to keep certain officials from testifying before Congress, perhaps most notably Don McGahn, the former White House counsel. McGahn was portrayed in the Mueller report as a key witness to some of the potential acts of obstruction of justice committed by Trump that Mueller documented in the report. McGahn was a private citizen when the House Oversight Committee subpoenaed him to testify, but the White House ordered him not to show up.
__ BUSINESS RECORDS The Democratic-led House Financial Services and Intelligence committees have subpoenaed information related to Trump's business records held by Deutsche Bank and Capital One. The panels want the information for their investigation into possible "foreign influence in the U.S. political process." Trump's lawyers have argued that Democrats lack a required "legitimate legislative purpose" in subpoenaing the records, but a federal judge refused in May to block the subpoenas. Trump appealed. The case is before a three-judge federal appeals court panel.