Republican dark money groups are outspending their Democratic counterparts by an incredible margin, according to data from the nonpartisan Sunlight Foundation.
During this cycle, conservative groups that do not disclose their donors have spent more than $94 million, while liberal dark money groups have spent more than $28 million.
The data this cycle confirms Republican dominance of dark money spending. In the 2012 election cycle, about 80 percent of dark money spending backed Republican candidates.
Although Republicans spent more through dark money groups, Democratic outside spending in general matched money spent by Republican outside groups, Sunlight noted.
The Sunlight Foundation also published a chart that tracks outside spending in twelve of the most competitive Senate races. The races in North Carolina, Iowa, and Colorado saw the most attention from outside groups.