Ted Lieu has a legal background, so his opinion on this is relevant. According to Wikipedia, he was military prosecutor before becoming a politician. He was the editor-in-chief of the Georgetown Law Journal, and he ran (unsuccessfully) in the California Attorney General election of 2010.
For reference, this is the law that Lieu is quoting from:
(b) Whoever knowingly uses intimidation, threatens, or corruptly persuades another person, or attempts to do so, or engages in misleading conduct toward another person, with intent to—
influence, delay, or prevent the testimony of any person in an official proceeding;
(2) cause or induce any person to—
withhold testimony, or withhold a record, document, or other object, from an official proceeding;
alter, destroy, mutilate, or conceal an object with intent to impair the object’s integrity or availability for use in an official proceeding;
evade legal process summoning that person to appear as a witness, or to produce a record, document, or other object, in an official proceeding; or
be absent from an official proceeding to which such person has been summoned by legal process; or
hinder, delay, or prevent the communication to a law enforcement officer or judge of the United States of information relating to the commission or possible commission of a Federal offense or a violation of conditions of probation  supervised release,, parole, or release pending judicial proceedings;
shall be fined under this title or imprisoned not more than 20 years, or both.