The RealClear final average of polls had the Generic Congressional Democrat ahead by 0.6%. But the actual total votes for Congressional candidates has the GOP up 1.1%. Should the Generic Congressional Ballot polls be "weighted" to reflect reality and add 1.7% to the GOP?
The GOP win in Congressional voting is somewhat surprising since Clinton won the popular Presidential vote by 2.1%. Why the disconnect between Presidential and Congressional voting? Did Trump perform 3.3% worse than a "real" Republican? Did third party presidential candidates predominantly attract GOP voters? If Trump had actually won the popular vote by 1.1% he would have won the additional states of NH, NV, MN, and ME.
There were a lot of Clinton/rep congressman vote downballot.