As Bobert says, we don't and can't really know how much has been spent on the anonymous-donor-sponsored "Independent" ads because the Republicans filibustered the bill that would have required disclosure of the sources.   Also, some ads that are explicitly about ballot measures are probably not "counted" as ads for any candidate or party, but if they're ads against, say, gay marriage or legalization of marijuana or for publicly financed campaigns, etc., they're almost certainly backed by Republican supporters, and there's almost always a lot more spent on ads against land-use planning, environmental protection, abortion rights, gay rights, gun control, tax levies, etc., than on populist type measures.

I'm glad you mentioned the 24-news-hour right-wing propaganda channel that calls itself Fox "News," Bobert.   In addition, right-wing talk radio air time is more than 9:1 compared to progressive or liberal talk radio - plus, in most parts of the country you can't find any progressive or liberal talk radio at all. Even if that were due to listener preference -- which is absurd, since the conservatives/Republicans hardly ever outnumber the liberals/Democrats in voting by more than 7:3 and it's usually a lot closer to 50:50 than to aything much more lopsided, even in many so-called "red" states and regions -- it still means that it's very hard for anyone in most parts of the country to hear information and opinion presented by liberals or progressives.

Between Fox News and talk radio, that's billions of $ being spent year round to disseminate Republican talking points and conservative-slanted "news" and opinion.