The primaries in deep blue Illinois on Tuesday were a test of who has power and influence in the Democratic Party. In three primaries for open U.S. House seats in the Chicago area and the seat of the retiring Senator Richard Durbin, it was the party’s progressive wing versus more moderate forces. In all four races, there was a candidate supported by Senator Bernie Sanders, Senator Elizabeth Warren, or both. And in all four races, there was at least one different candidate who had support from