The Democratic establishment is alarmed that a top candidate’s collapse and the surge from a democratic socialist could cost them the governorship.Sara Rodriguez had a prime opportunity this past Saturday to show voters gathered for a gubernatorial candidate forum in Wisconsin’s rural Northwoods that she was the person who could unite Democrats, thwart a democratic socialist insurgency and deliver the party unified control of state government for the first time in a generation. Except the lieutenant governor didn’t show up. Her reserved table sat empty, save for a lone campaign sign. She blamed the last-minute cancellation on a family emergency....