Polls suggest that more and more, opposition to Obamacare is based on voters' personal experience, and not just on what they have heard or read about the law.

That does almost nothing to address voters' concerns, which remain a potent factor in the campaign. The bottom line is, there's a reason Republicans keep pushing so hard against Obamacare: So far, it's working.

The Obama damage is two-fold. First, his success relied on a coalition that likely will not survive, or at least survive at full strength, without Obama himself on the ticket. Secondly, Obama drove a significant portion of white voters away from the Democratic Party.

If one cannot imagine Obama saying such a thing — well, he didn't.

As Democratic losses mounted in Senate races across the country on election night, some liberal commentators clung to the idea that dissatisfied voters were sending a generally anti-incumbent message, and not specifically repudiating Democratic officeholders. But the facts of the election just don't support that story.

So Republican candidates bash Obamacare and move up in the polls. Given that public opinion remains firmly against the health care law - as it has been for years - that's not a shock. Democratic beliefs to the contrary are probably wishful thinking.

Now that the 2014 elections are over and national politics is all about 2016, Democrats have good reason to worry that, for all his success at the polls, President Obama will leave his party with a toxic legacy.