Brookings fellow Niam Yaraghi looked at both Koch spending on anti-Obamacare ads, and enrollment data for the law. Here's a graph of his findings:
In fact, after controlling for other state characteristics such as low per capita income population and average insurance premiums, I observe a positive association between the anti-ACA spending and ACA enrollment. This implies that anti-ACA ads may unintentionally increase the public awareness about the existence of a governmentally subsidized service and its benefits for the uninsured. On the other hand, an individual’s prediction about the chances of repealing the ACA may be associated with the volume of advertisements against it. In the states where more anti-ACA ads are aired, residents were on average more likely to believe that Congress will repeal the ACA in the near future. People who believe that subsidized health insurance may soon disappear could have a greater willingness to take advantage of this one time opportunity.So the Kochs have been spending on what are basically a bunch of public service announcements letting people know they might be able to get subsidized health insurance. Good deal! All those millions might not have been wasted after all.