This post has been updated.

When it strikes midnight on Federal Election Commission filing day, political nerds wait with bated breath for the numbers and expected transcendence to fall. In an age when horse race coverage depends on data to map out election cycles with increased precision, polls and campaign finance forms are among the best weapons the media has.

And, there are always obvious things to learn from the filings, as Aaron Blake and Sean Sullivan showed in yesterday's Morning Fix. However, it is also easy to be misled by the FEC filings, especially this early in the 2014 race -- and especially this early in the 2016 presidential race. Just because the money isn't reported doesn't mean it isn't there.

There's the 501(c)4s for starters. According to FEC rules, these nonprofits are exempt from revealing their donors. They also don't need to file independent expenditure reports unless they run explicitly political ads, or electioneering ads close to the election. These coveted perks are are among the reasons 501(c)4s and other 501(c) organizations mostly known for their political advocacy try so hard to keep distance from explicit endorsements of candidates or electioneering. Losing their tax-exempt status would make them no different from a super PAC — and likely make some donors shy away from giving.

At first glance, documented outside spending from the FEC makes it appear that Democratic outside groups are outspending Republican outside groups; the top four groups when it comes to spending so far this cycle all attack Republicans or support Democrats. The instantaneous assumption that Democrats are closing the outside money gap with Republican that immediately formed after the Citizens United decision obscures the fact that several Republican 501(c)4s would likely best them all if they had to file too.

These groups reported more than $400 million in spending to the FEC during the 2012 election cycle -- which is likely a small fraction of their total spending.

If you think about it, this spending, as of yet invisible to the FEC, should be very clear to anyone living in a state with a close senate election, where it has been on display for months. If you managed to miss the ads, the Democratic Senatorial Campaign Committee has been trying to fill the country in, realizing that this cash is what could do them in despite their nice showing in the first quarter report. Yes, we're talking about Americans for Prosperity, a 501(c)4 backed by the Koch brothers that has already spent tens of millions on television advertisements in close election cycles. And, they are spending vast amounts more than the top Democratic outside groups, the Senate Majority PAC and the House Majority PAC, as this chart shows.

Americans for Prosperity spent big in 2012 too — they reported $37 million to the FEC, but spent a total of $140 million according to additional reports — but was rivaled by Republican super PACs on the federal level, like American Crossroads and Restore Our Future (Americans for Prosperity is also active in state and local races across the country, so that number misses the whole picture of their past campaign spending). Right now, at least, Americans for Prosperity is playing point guard. Another unknown factor in the picture of Republican outside spending is Crossroads GPS, a 501(c)4 that spent $71 million in 2012 federal election. It hasn't been a big player in the 2014 midterms yet, but again, it's only April, and we have no idea how much money they could have raised.

Another problem with putting too much faith in early FEC filing is knowing how much spending and donating is going to change as the election grows closer. Many reporters and commentators made much of the fact that Americans Crossroads, the super PAC sister to Crossroads GPS started by Karl Rove, was a complete couch potato in 2013, doing little fundraising or campaigning. However the group raised $5.2 million alone in March. You can expect that number to climb as the election gets closer for the super PAC that spent $105 million during the 2012 election. Other conservative 501(c) groups — like Americans for Tax Reform, the American Future Fund and Freedomworks — are likely to start spending noticeable money soon too. Liberal 501(c)4s — like the League of Conservation Voters — are out there too, but they don't have the clout that their siblings on the right do. While Democrats have mostly limited their outside spending to super PACs and unions, Republicans have shifted more and more to using nonprofits for political spending. It's not clear that one is more successful than the other, but 2014 is shaping up to be a contest between these two different outgrowths of Supreme Court decisions on campaign finance from 2010.

However, again, it's only April. After primary season ends, summer races by, and September finally comes, outside spending is going to be nuts. As this chart by the Sunlight Foundation shows, spending by 501(c)4s and other groups that don't need to file quarterly FEC reports went crazy in the last few months before Election Day — especially from Republican groups. With so many tough primaries featuring much Republican infighting, the more prominent super PACs are probably waiting to learn the final candidates before they choose their battles.



Source: Sunlight Foundation

Long story short, if there's one thing the 2010 and 2012 elections showed us, it's nearly impossible to get a good read on outside spending while the election is happening — especially before the general election begins. Groups that spend loads early on may be beat as the election nears, and groups that spend loads may not be able to keep a doomed candidate afloat. One thing we can definitely learn from the first quarter filings, though? The 2014 midterms are going to be one pricey election cycle — not that we needed much proof of that.

Must-reads:

"Obama aims to reinvigorate Asia strategy" — David Nakamura, The Washington Post

"With Eyes on 2016, Perry Is Mired in the Past" — Manny Fernandez, The New York Times

Correction: The post has updated language on the filing requirements of 501(c) groups and Americans for Prosperity's spending during the 2012 election cycle.