CBS and AMC returned to being Sunday night’s leaders — CBS with total viewers (8.66 million), AMC with all key demos (2.5 adults 18-49 rating, 2.1 adults 18-34 rating, 2.8 adults 25-54 rating). On the night, PBS aired the series finale of “Downton Abbey” while CNN aired the seventh “Democratic Presidential Debate” from Michigan — […]