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.

'I haven't used the veto pen very often since I've been in office,' Obama told NPR. 'Now, I suspect there are going to be some times where I've got to pull that pen out. And I'm going to defend gains that we've made in healthcare; I'm going to defend gains that we've made on the environment and clean air and clean water.'

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.

Voters replaced Democratic senators with Republicans in Arkansas, Colorado, Iowa, North Carolina, Montana, South Dakota, West Virginia, and likely in Alaska, and appear on track to do so in a runoff next month in Louisiana. At the same time, voters kept Republicans in GOP seats in heavily contested races in Georgia, Kansas, and Kentucky. That is at least ten, and as many as a dozen, tough races, without a single Republican seat changing hands. Tuesday's voting was a wave alright - a very anti-Democratic wave.

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.

In the end, no single group will mean defeat for the Democrat and victory for the Republican in 2016. But President Obama's troubling legacy - a weakened coalition and growing ranks of alienated white voters - could mean a serious post-presidential hangover for Democrats.

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.