There is no trend. You need 15 polls for a reliable guide. The early figures are misleading. I have Trump +3.5 to +4.5 the whole time once you have adequate polls. The graph looks pretty but is pretty useless.
Lets say you have 12 judges scoring a dance. The contestants are wearing red and blue. 9 judges are blue biased and 3 are red biased.
Which combined scores do you use to calculate the most accurate score?
Years of data. The same bias is still there. I correctly predicted all 7 swing states using this. You guys had no clue. Years of Trump abuse and not 1 clue on the poll bias.