Tonight on The Last Word: Donald Trump fails to get 55% of the New Hampshire primary vote. Also, Florida Democrats flip a state House seat in a special election. Plus, a Washington, D.C. appeals court again rejects Trump's gag order appeal. And the civil defamation suit against Trump will resume Thursday. Simon Rosenberg, Rep. Maxwell Frost, Florida State Rep. Tom Keen, Glenn Kirschner, and Barbara McQuade join Lawrence O'Donnell.