Rep. Adam B. Schiff is promoting a new anti-Trump witness whose public allegations have been met with vehement denials and at least one lawsuit. Lev Parnas and his attorney have been lobbying to become a star Schiff impeachment witness in a Senate trial as part of the congressman’s drive to remove President Trump from office. Mr. Schiff, California Democrat and chairman of the House Permanent Select Committee on Intelligence, injected Mr. Parnas last week into the impeachment record. He and other Democrats released two troves of Parnas downloads from his various electronic devices including texts, emails and photos of himself...