“They shall not be questioned”

Watching the impeachment hearings, one question nagged. Why is it illegal for citizens to lie to Congress, but legal for members of Congress to lie back to them? So I looked up the answer, which came in two parts. First, sworn witnesses testifying before Congress lie at risk of perjury charges. Meanwhile, members of Congress can say what they like under protection of no less than Article 1, Section 6 of the Constitution. It is the limits of this protection, known as the Speech and Debate Clause, that are now at the heart of the tug-of-war over whether the impeachment charges against President Trump will be referred for a Senate trial. Central to refusal of the President and Senate Majority Leader to call the Secretary of State, Chief of Staff, and former National Security Advisor to testify on behalf of Mr Trump is that they would be sworn witnesses whose …