http://www.brennancenter.org

Dark money” is spending by groups that hide the identities of some or all of their donors.

The analysis below details not only the record amounts of outside spending in 2014, but also the dominance of “dark money groups,” which are outside groups that don’t reveal all the sources of their funds. For the first time, the Senate changed hands because of the victories of several candidates who were overwhelmingly backed by these groups. Ten winning candidates together benefited from $127 million in dark money – more than 70 percent of the nonparty outside spending in their favor. The victors will take their seats likely feeling grateful to interests that are hidden from their constituents and the public.