Democrats’ lead in the generic congressional ballot narrowed to 2 points in a Politico-Morning Consult poll released Wednesday. The poll found that Democrats led Republicans in the ballot 45 percent to 43 percent, down from the 5-point lead they had in the same poll last week. Democrats are holding the narrow lead six weeks out from the crucial November midterms. Democrats are seeking to defy a historical trend that usually sees the president’s party lose seats in Congress in the midterm elections, while Republicans are trying to retake control of both chambers.