The decision had an immediate impact. Within five months, roughly 300 donors had combined to give more than $11 million in contributions that would have been illegal before McCutcheon. That newly unleashed spending—representing only a fraction of all that these donors gave—is more than the cost of an average winning Senate campaign. But more notable than the amount of money spent is the fact that so few donors were able to spend it.
A Year Later, McCutcheon Has Invited More Money from Fewer Donors | Brennan Center for Justice
