Even if you are in office you can lie to the public all you want. For politicians there is a federal court case that says they can. It’s John Q. Publics’s job to catch them and not be so gullible. Just don’t lie where it’s sworn testimony, unless you’re Slick Willie.
Maybe they need to revamp that oath of office they take to include that "I will not now, nor during the remaining days of my term of office, ever use false information, innuendo, or rumor, to further myself publicly, politically, and monetarily.