More than $1.6 billion has been spent or booked on TV ads in a dozen Senate races, with $3 out of every $4 being spent in six states — Georgia, Pennsylvania, Arizona, Wisconsin, Nevada and Ohio, according to an NPR analysis of data provided by the ad-tracking firm AdImpact.
Most of that money is coming from dark money outside groups with little-to-no donor transparency — and Republicans are getting a huge boost from them.
