Republicans dominated the midterm elections in 2010 and 2014 in part because voters who supported Barack Obama in presidential years voted for Republicans or stayed home when he wasn’t on the ballot.
The turnout advantage Republicans enjoyed during the Obama years may no longer exist as we head into 2018, and in fact, there are some signs that Democrats may be the one with a decisive turnout advantage this cycle.
This shift in reality may not be reflected in much of the high-quality polling so far this year because much of it has been done among registered voters instead of the more refined category of likely voters. In other words, current polling may not fully reflect Democratic strength heading into the midterms. CONT.
Harry Enten, CNN