Key findings:

  • Spending by outside groups (nonprofits, super PACs, and other non-candidate organizations) totaled at least $209 million in 38 states in the 2012 election cycle.
  • Pro-Democratic groups, many associated with unions, outspent their Republican counterparts by more than $8 million in those states.
  • More than one out of every two dollars spent originated from groups funded primarily or entirely by out-of-state donors.
  • The Republican Governors Association, backed by conservative billionaires and large corporations, spent at least $34 million, making it the single biggest outside spender in the analysis.
  • The Supreme Court’s Citizens United ruling made it easier than ever for outside groups to raise and spend cash on state races — the ruling invalidated restrictions on corporate and union spending in 24 states.
  • In New Hampshire, outside spending groups outspent the candidates themselves and spent at least $24 per registered voter.