It's no secret that Republicans believe that the fumbles and foibles of Obamacare are their golden ticket to winning back the Senate majority in 2014. Already there has been considerable spending by outside conservative groups on ads targeting Democratic senators in Republican-leaning states -- Arkansas, North Carolina, etc. -- who are up for reelection this November.

But, there's another potential impact -- beyond the political one -- of these early ads, according to Elizabeth Wilner, senior VP at Kantar Media Ad Intelligence. "This isn’t just about using the issue to defeat Democrats, though that’s emerging as the primary goal for 2014; it’s also about rendering the law unsuccessful," explained Wilner. "It’s a quirk of geography, and of political demography that has been decades in the making, that vulnerable Democratic incumbents represent a lot of areas where there are a lot of Americans who need health coverage."

In other words, the most vulnerable Democratic senators up for reelection in 2014 represent a remarkably large number of people who are uninsured. That means that ad spending on anti-Obamacare messaging in those states is -- and will continue to be -- higher than the national average despite the fact that, in theory, more people in those states might benefit from the law.

Here's a map of ad spending by media market on anti-Obamacare ads -- courtesy of Kantar Media CMAG. (This map first appeared in the Cook Political Report.)

Now, here's what the map looks like if you focus on  media markets where the percent of uninsured is between 20 and 25 percent.


You'll see that there is a remarkable overlay of those media markets and competitive Senate seats held by Democrats. In the Raleigh-Durham (N.C.) market, for example, 21.7 percent of the people are uninsured, and/but it has seen more than $700,000 in anti-Obamacare ads in 2013. Ditto the Little Rock-Pine Bluff (Ark.) media market, where almost one in four people are uninsured and more than $500,000 has been spent on anti-Obamacare messaging. And the Charleston-Huntington (W.Va.) media market with 23.2 percent uninsured and almost $130,000 in anti-Obamcare ad spending.

The ads bashing Obamacare in these states will only increase as the election draws closer. Not only does it imperil the Democratic incumbents in these places, but it also may well endanger the law's chances of success in these areas.