[ad_1] When former President Donald J. Trump goes on trial on Monday in Manhattan, President Biden and his allies are not likely to say much. For Democrats, a former president facing criminal charges over covering up a sex scandal surrounding the 2016 campaign speaks for itself. The media coverage will be constant, especially if Mr. Trump takes the stand, which he has floated as a possibility. And while Mr. Trump faces up to eight weeks in court, Mr. Biden will be on the campaign trail and employing a “Rose Garden…