As I wrote earlier today, Obamacare has really faded as an electoral issue this year. What makes the even more striking is the sheer volume of negative ads it has withstood -- with almost nothing to counteract those negative messages.

The below chart from the Wesleyan Media Project shows precisely how big that imbalance has been.

While more than 160,000 ads have aired against Obamacare since Jan. 1 -- more than one-quarter of all political ads -- fewer than 10,000 have mentioned the law in any other context. That means not negative, but not necessarily positive either (many occupy something of a neutral territory). All told, it's more than a 17-to-1 margin.

In that context, the fact the Obamacare has slipped as a priority is even more surprising.

But the anti-Obamacare forces also appear to be taking notice. While 42 percent of ads were anti-Obamacare during the open enrollment period, just 23 percent have been since. But that's still 23 percent -- and of a much-larger pie of political ads (closer to election=more ads).

The question from here is whether that 23 percent continues to slip, as it appears Obamacare isn't a particularly important issue for a ton of voters.