Lawyer of whistleblower in Trump impeachment case sues administration over revoked security clearance

A lawyer who represented a government whistleblower in a case that led to President Donald Trump's first impeachment sued the Trump administration on Monday for "unconstitutional retaliation" after his security clearance was revoked.

Lawyer Mark Zaid argued that the administration's decision to pull his clearance in March was in retaliation for representing former Department of Homeland Security intelligence chief Brian Murphy, who was key to Trump's 2019 impeachment.

Murphy filed a whistleblower complaint in 2019 alleging Trump, amid his re-election campaign, pressured Ukrainian President Volodymyr Zelenskiy to investigate then-U.S. presidential candidate Joe Biden and his son Hunter's business dealings in Ukraine. 

The U.S. House of Representatives voted later that year to impeach Trump for abusing the power of his office and obstructing Congress, but he was later ac...