A lot of has changed for the better in the nation’s capital since Donald Trump returned to the White House. But the recent arrest of a young National Guardsman for an apparently harmless breach of D.C.’s constitutionally questionable gun control regime shows the District still retains its longstanding anti-gun streak. If D.C.’s own public officials can’t be trusted to administer the law with proportionality and common sense, higher authority should intervene.