I always used to reference the RCP poll summaries (Real Clear Politics) but haven’t recently. Seems they are doing something new this time around, and I think it is quite interesting. PJ MEDIA explains:
So this year, RCP added a column for the average amount polls underestimated Republicans over the past few elections and then a column for adjusted poll averages. The last column is the site’s predictions for the Senate and governor races. RCP now predicts the Senate will have a 54-seat Republican majority after a runoff in Georgia in December. It also forecasts the GOP will net three governorships, leaving 19 Democrat-led states and 33 Republican-led ones.
I hope they are right!