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.

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.

In the end, Tuesday's vote represented a repudiation of virtually every notion Democrats embraced in recent weeks as they tried to disregard the growing evidence that they were headed for a historic defeat. Now, the vote is in, and the voters' message can no longer be discounted.

Some Democrats and their advocates in the press believe Obamacare, a year into implementation, is no longer much of a factor in the midterm elections. But no one has told Republican candidates, who are still pounding away at the Affordable Care Act on the stump. And no one has told voters, especially those in states with closely contested Senate races, who regularly place it among the top issues of the campaign.

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.

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.

'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.'