From internal party polls to retirements in the House and more, CNN's chief data analyst Harry Enten counts down the 8 most overlooked midterm election indicators. 0:00 Harry Enten's top 8 hidden midterm election signals 0:19 Signal 8 1:22 Signal 7 3:36 Signal 6 4:19 Signal 5 5:56 Signal 4 7:31 Sig...