United States

Impeachment witness asks federal judge to decide if he is obliged to testify

(CNN)A key witness in the impeachment inquiry has sought for a court to decide if he should testify, caught between a House subpoena and a demand from White House to protect President Donald Trump's immunity from testifying to Congress.Charles Kupperman, who served until last month as deputy national security adviser at the White House, filed a lawsuit Friday asking a federal judge to rule on whether he is obliged to testify before House investigators. The case presents a new challenge to House Democrats seeking cooperation from close aides of Trump.Kupperman, who worked closely with former national security adviser John Bolton, is scheduled to sit Monday for questioning by the three House committees handling impeachment."Plaintiff is face ...