@mystery-ak The Democrats AND Republicans used Fusion GPS, a Washington opposition research company, to do background research on Trump (Democrats paying), and background research on Hillary Clinton (Republicans paying).
Every candidate, if he/she is serious, pays for opposition research on those running against them. The Republicans quit Fusion GPS at some point.
It is Fusion GPS who found the material about Trump which included the dossier. The Democrat Party didn't know what Fusion GPS would find. There was no point in Comey saying who paid for the information - the point was Fusion GPS found it. I have read how Fusion contacted people that resulted in the dossier. It was Fusion who found it, not the Democrat Party.