According to a projection based on the Center for Responsive Politics' analysis of Federal Election Commission reports, the total amount of money spent on congressional races in this election cycle is expected to reach $5.2 billion, a 35 percent increase from the 2014 midterms.
This includes money spent by candidate campaigns, party committees and various outside groups. With a total of 1,661 Democratic House and Senate candidates and 1,471 Republican candidates, so far, a total of $1.26 billion has come from the Democratic side and a little shy of $890 million has come from the Republican side.
More than $1.3 billion in outside spending has come from more than 3,200 outside groups, including party committees, super PACs and political nonprofits, marking a 60 percent increase from 2014.
Most expensive races
Top Senate races:
Democratic Sen. Claire McCaskill's vulnerable seat in Missouri has brought in more than $76 million from outside groups to the Missouri Senate race. Conservative groups led by Senate Leadership Fund, the National Republican Senatorial Committee and Americans for Prosperity, have spent more than $41 million in support of Hawley, while liberal groups have spent more than $35 million in support of McCaskill. Meanwhile, incumbent McCaskill's campaign has outspent Hawley by far, with the vulnerable Democrat spending more than $33 million and the Republican challenger spending $7 million.
Top House races:
In the lower chamber, a toss-up between two minority candidates in California's 39th Congressional District, where immigrants make up a third of the population, has brought in the most money. Democrat Gil Cisneros' campaign has spent $10.5 million, while Republican Young Kim has spent just about $2 million. Kim has a strong backing of House GOP leadership though, with its super PAC Congressional Leadership PAC boasting a $6.3 million in support of Kim. House Democratic leadership is also behind Cisneros, with House Majority PAC and DCCC spending more than $5.2 million in the race.
GOP Rep. Dana Rohrabacher's effort to defend his seat in California's 48th district has also become increasingly expensive, with candidate campaigns spending nearly $13 million and outside groups pouring in nearly $20 million. The Democratic side is eager to unseat the vulnerable Republican, with challenger Harley Rouda leading an aggressive $6 million campaign, and liberal outside groups including Independence USA PAC, House Majority PAC and DCCC spending more than $11 million to back him. Rohrabacher is backed by Congressional Leadership Fund's $4 million campaign.
Top outside groups