I think the increasing premiums played a very large part in Trump winning. I'm an independent who voted for Clinton, but I suspect that the democrats will not back away from supporting their unpopular healthcare law even in 2018 and will fail to take back the majority from either house.
It was so unpopular, it screwed democrats over in 2010. Instead of dropping the issue, they pushed even harder and now Trump is president, republicans own both houses, and the next few supreme court justices will be conservative. Whether you agree with Obamacare or not, I'd say you're in denial if you don't see that as one of the main reasons for losing both 2010 and now.
"we lost because not enough people went out to vote" is like saying "We lost because we didn't score enough touchdowns." Indeed, getting people to vote for you is the name of the game. Duh.
The question is... will democrats keep pushing mandatory corporate insurance and rising premiums, or will they come up with a better idea that can actually win back congress?
(even though I am clearly attacking obamacare, the point of this post is to explain why I think the republicans own the government, not to argue principle. Republicans own congress for a reason)