Big bucks, shadowy companies: Election mystery money returns 

WASHINGTON (AP) — Campaign money from shadowy sources is back this presidential election.

At least $4 million of it is flowing to outside groups helping White House hopefuls, making it difficult to trace who’s behind the big bucks. Both parties benefit from money routed through obscure corporations, or from nonprofits that don’t have to disclose their donors.

The contributions are a reminder of fe...