Sen. Kelly Ayotte (R-N.H.) is the only 2016 candidate so far to benefit from both personal contributions by the Kochs and outlays by one of its outside spending groups. (AP Photo/Alex Brandon)

To anyone who follows politics, the Koch brothers are best known for spearheading a sprawling network of groups that invest millions in conservative, libertarian-leaning candidates and causes. It’s assumed that Charles and David Koch and their wives have put a great deal of money into these organizations — but it’s hard to know for sure, since most of them operate under sections of the tax code that don’t require them to disclose their donors.

What we’re left with, then, is the tip of what’s believed to be a very large iceberg. But it’s all we have, so let’s take a look.

According to FEC filings, the Koch brothers have personally donated more than $4 million to campaigns and outside groups during the 2016 cycle so far. That’s a lot of scratch, though of course not by the standards of what the billionaire industrialists could give.

Surprisingly little of it has gone to candidates. The bulk — $3 million, in one lump sum — was given by Charles Koch at the end of May to Freedom Partners Action Fund, a super PAC in the brothers’ tangled election financing machine and an offshoot of the network’s hub, Freedom Partners Chamber of Commerce. Boosted by another $3 million given by Charles Koch’s trust back in December (which we didn’t count toward the brothers’ personal donations), Freedom Partners Action has spent $13.25 million attacking a quartet of Democratic Senate hopefuls: former Gov. Ted Strickland (Ohio), former Sen. Russ Feingold (Wis.), former state Secretary of Environmental Protection Katie McGinty (Pa.), and former state Attorney General Catherine Cortez Masto (Nev.). Strickland has taken the most punishment – almost $6.2 million – from Freedom Partners, which is one reason the Ohio Senate race has the highest outside spending of any congressional contest so far.

The second highest sum from the Koch family went to Team Ryan — $488,000 from Charles and his wife Elizabeth to the joint fundraising committee that supports House Speaker Paul Ryan and his leadership PAC, Prosperity Action, and the National Republican Congressional Committee (NRCC), the main fundraising arm for the GOP in the House.

After that comes the $233,800 David Koch has given to the National Republican Senatorial Committee, and $160,000 that he and wife Julia contributed to the NRCC.

A measly $46,900 has gone to candidates — all from David and Julia Koch, who have personally invested in six individual Republican campaigns in the 2016 election cycle.

The couple has donated $10,800 – the maximum – to New Hampshire Republican incumbent Sen. Kelly Ayotte, who is facing a formidable challenge for her seat from current Gov. Maggie Hassan, a Democrat.

Last November, they also maxed out to Sen. Roy Blunt of Missouri, in whose state one of the Koch companies operates a 580-mile pipeline. Blunt has a credible Democratic challenger, the Missouri Secretary of State, who raised impressive sums in the first quarter of 2016.

The two also gave the full $10,800 to Sen. Jerry Moran, a Republican who represents Kansas, where Koch Industries is headquartered. Their generosity appears to be motivated by neighborly good will, since Moran has little to fear in his re-election bid.

And they helped subsidize a losing candidate, giving $10,800 to support August “Augie” Wolf, a Republican who sought the Connecticut Senate seat now occupied by Democrat Richard Blumenthal. Wolf lost in the primary to Dan Carter.

Sen. Orrin Hatch (R-Utah) was another beneficiary of the Koch largess, though he’s not up for re-election this cycle. David Koch donated $5,000 each to OrrinPAC and Hatch Victory Committee in April 2015; the former is Hatch’s leadership PAC, while the Victory Committee is a joint fundraising vehicle that has sent most of its money to the NRSC.

Among their smallest contributions, David Koch sent $1,000 to the New York Republican Federal Campaign Committee, which supports Republicans in that state running for federal office. And Julia Koch donated $2,700 to Rep. French Hill (R-Ark.), and $1,000 to Andrew Heaney, a New York Republican who recently lost his primary.

The Kochs gave to another loser: former House Speaker John Boehner (R-Ohio). Boehner’s joint fundraising committee got $100,000 in David Koch dollars last September — three days before Boehner resigned as speaker, making way for Ryan (whose joint fundraising committee received nearly half-a-million dollar from Charles and Elizabeth, as noted earlier).

The big bucks

Oddly, the map of races in which the Kochs have made personal contributions doesn’t line up with where their network of outside spending groups has been active. In fact, the only race where there seems to be overlap between Koch personal spending and Koch network spending is the New Hampshire contest between Ayotte and Hassan.

Koch Table

Neither Freedom Partners Action Fund, the super PAC, nor Americans for Prosperity (AFP), the main dark money group in Koch world, has reported spending to the FEC on that race. That doesn’t mean it hasn’t run ads there — last summer, for example, AFP said it spent $1.2 million on issue ads attacking Hassan for tax hikes; unless an election is close at hand, groups like AFP don’t have to tell the FEC about their outlays for these types of ads, which don’t expressly ask the public to vote for or against someone but instead cast candidates positively or negatively in connection with some policy issue.

And a report by the Center for Responsive Politics and Wesleyan University found that as of May 8, AFP had aired $4.6 million worth of TV ads mentioning Senate candidates in the 2016 cycle. These ads were split between Ohio, Wisconsin, and Ayotte’s New Hampshire.

Furthermore, AFP hasn’t been silent in other Senate races. In the 2016 cycle, the group has disclosed over $1.7 million in spending to the FEC, mainly directed against Democratic Senate challengers Strickland, McGinty and Feingold. Freedom Partners Action Fund has spent its $13.25 million in these same races, as well as in Nevada. (The more than $15 million that AFP and the Freedom Partners super PAC have reported spending to date this cycle sharply contrasts with the $83,606 that Koch groups reported spending at around this point in the 2012 election cycle.)

As for other groups in the Koch orbit, Concerned Veterans for America hasn’t reported spending to FEC during this election cycle, but had aired $1.6 million worth of issue ads in Nevada and Pennsylvania by May 8.

Similarly, the Libre Initiative, an organization that seeks to bring Hispanic voters over to the Koch small government value system, hasn’t reported any independent expenditures. But it has been amply funded by the mother ship, Freedom Partners Chamber of Commerce, and is expected to spend over $9 million this cycle.

And Generation Opportunity – a Koch group aimed at millennials – likewise hasn’t spent on TV or reported any expenditures to the FEC. But the group advertised heavily in 2014, and may do so again closer to November.

Finally, there’s always room in the box of tricks for some old-school campaign finance strategy: Koch Industries PAC, the political action committee of the Kochs’ main company, has been busy as ever this cycle, distributing a total of $859,400 to the campaigns of 156 Republican House candidates plus another $176,500 to 23 GOP Senate campaigns, not to mention a cumulative $382,000 to Team Ryan, the NRSC, and the NRCC. The Koch brothers donated $16,248 of the $2.8 million the PAC has raised so far.