That noise you don’t hear is the sound of 501(c)(4) groups popping up all over Washington as Senate Republicans prepare to find themselves back in the majority next year. These “dark money” nonprofits, so called because they don’t require donor disclosures and can take a year to be listed, are a sort of going-away present from the retiring Mitch McConnell, who’s given these fundraising vehicles his implicit blessing by not raising any objection to them. “There’s been an explosion of (c)(4)s on the Republican side,” one lobbyist told me. Said another: “You can take unlimited sums of cash, you can have a sugar daddy or a sugar momma.”