Last week, the Maryland Democratic Party crowed about a poll showing Lt. Gov. Anthony G. Brown with a 14-point lead over Republican Larry Hogan. The Hogan campaign, the state GOP and others -- including the American Association of Public Opinion Research -- have questioned that poll's methodology, but the biggest reason to doubt its veracity is the behavior of the Brown camp itself. If Mr. Brown and his fellow Democrats think that poll is accurate, they're sure not acting like it. Since last week, Mr. Brown and the state Democratic Party have only intensified their attacks on Mr. Hogan — some of them fair game, some not. That suggests this race is still competitive. But unless Mr. Hogan finds a more effective way to respond, it won't be for long.