Now that 2015 is over and voting in the presidential contests has begun, we shouldn’t forget about the members of Congress — you know, the ones in charge of making the laws — who are up for re-election. Outside groups are raising tons of cash in an effort to influence our congressional elections. According to Sunlight’s Real-Time Influence Explorer, super PACs spent $346.5 million in 2014. Add a presidential contest on top that, and we are in for a ride.

While not all seats are competitive, many are still close: Rothenberg & Gonzales Political Report rates 34 House races as competitive and 12 Senate races as competitive, putting a lot at stake in the upper chamber. The Democrats need a net gain of five seats to gain the majority in the Senate, while they face a steeper climb in the House, needing a net gain of 30 seats.

Let’s take a look at who these outside groups are raising money from now that we have updated numbers from the most recent filings from the end of 2015.

Key Democratic super PACs

There are two flagship super PACs supporting Democrats in 2016: House Majority PAC and Senate Majority PAC. The two groups ended the year with $6 million and $5.4 million cash on hand respectively.

Big donations to House Majority PAC, which picked up $5.8 million in the back half of 2015, came from liberal megadonors Fred Eychaner and Donald Sussman, each of whom gave $1 million. Other contributors writing six-figure checks include several unions — IBEW PAC Educational Fund, LIUNA, SEIU, the United Auto Workers and others — whose combined total giving was $1 million.  

Senate Majority PAC also raked in money from similar unions, with six-figure contributions from United Auto Workers, SEIU, American Federation of State, County and Municipal Employees and IBEW. The group raised $7.7 million during the latter half of 2015.

There is one curious big ticket contribution — a $100,000 donation from Masimo Corporation, a medical device company located in Irvine, Calif. Just two weeks after that check was reported, Tom Harkin — a former Democratic senator — joined the company’s board. Masimo is also ramping up lobbying efforts, opening its first D.C. office to lobby on issues like the medical device tax, which it has done multiple times before. Masimo has received more than $9 million in government contracts.

Key Republican super PACs

Similar to the Democrats, the GOP has two flagship super PACs, one for each chamber. The GOP groups are generally a bit more fractured, with the proliferation of the Koch network and Tea Party groups that also spend big on congressional races.  

The Senate Leadership Fund raised $6.7 million in the last six months of 2015. Much of that came from big oil: According to Real-Time, Chevron, Petrodome Energy and Access Industries Inc. (a holding company that owns, among other things, Warner Music Group) all contributed $1 million. Warren Stephens, an investment banker, also gave $1 million, and Devon Energy threw in $750,000. This means $4.75 million of Senate Leadership Fund’s $6.7 million haul came from just four companies and one individual.  

The fundraising level from the House-focused Congressional Leadership Fund was much less robust, generating just over $100,000 over the second half of 2015. The group did receive one check for $102,975 from the American Action Network, a 501(c)(4) organization that does not have to disclose its donors. The group has $865,793 cash on hand.

Your very own super PAC

There are many super PACs that are set up for one election or a slate of candidates that support one issue: for example Indiana Jobs Now, which is supporting Republican Trey Hollingsworth for a House seat, and Women Vote! ($1.5 million cash on hand), the super PAC arm of Emily’s List, which is dedicated to electing pro-choice Democratic women. So far Women Vote! has only spent money on behalf of Rep. Donna Edwards, D-Md., who is running for Senate. It’s still early so expect more outside groups to establish their own super PACs.  

On the Democratic side we can expect Planned Parenthood Votes, the League of Conservation Voters Victory Fund, NextGen Climate Action and myriad others that were active in 2014 to jump into the congressional mix.

Tea Party and other conservative groups like Club for Growth Action, The Tea Party Majority Fund and Ending Spending Action Fund have already spent on congressional candidates. ESAF, for example, has spent more than $1 million on the New Hampshire Senate race between Sen. Kelly Ayotte, R, and her challenger, Gov. Maggie Hassan, D-N.H. ESAF’s big donors are Linda McMahon, a two-time Senate candidate and founder of World Wrestling Entertainment, and conservative megadonor Paul Singer.  

Dark money groups

Though these groups can still engage in political activity, we are not able to trace who is funding 501(c)(4) groups like American Action Network. Though these “dark money” groups will attempt to make an impact in congressional elections across the country, we can occasionally track their spending through independent expenditure filings. For example, the Koch-backed 501(c)(4) Americans For Prosperity does not reveal their donors, but we do know when it spends money on ads strictly opposing or supporting a candidate; this filing shows that AFP has spent more than $1.3 million in ads opposing Rep. Ted Strickland, D-Ohio, who is running for U.S. Senate.  

In the 2014 elections, dark money groups spent upwards of $145 million on independent expenditures — and that does not include so-called “issue ads,” ones which don’t explicitly advocate for or against a candidate. If trends hold, we can expect 2016 to another record-breaking year for dark money spending around congressional elections.

An ol’ fashioned party (committee)

And then there are the parties’ congressional committees: the National Republican Senatorial Campaign Committee, Democratic Senatorial Campaign Committee, Republican National Congressional Committee and the Democratic Congressional Campaign Committee. So far none of the groups have spent a significant amount in independent expenditures, but be ready: In 2014, the congressional campaign committees spent $226 million on independent expenditures.

Haven’t had enough of the congressional money race? Did we miss any big checks coming into congressional super PACs? Let us know, and check out our House and Senate candidate filings page to get an overview on who is raising the most money into their campaign coffers.