Mysterious docs retrieved from meth lab show inner workings of "Dark Money"

A strange story from Frontline and ProPublica: "Found in a meth house in Colorado, they were somewhat of a mystery, holding files on 23 conservative candidates in state races in Montana. They were filled with candidate surveys and mailers that said they were paid for by campaigns, and fliers and bank records from outside spending groups. One folder was labeled “Montana $ Bomb.” The documents pointed to one outside group pulling the candidates’ strings: a social welfare nonprofit called Western Tradition Partnership, or WTP." You'll want to watch the related Frontline documentary.