Scott Walker's early exit from the presidential primary has led some media outlets to conclude that super PACs may not be having as big an effect on the 2016 campaign as it was once thought they would. However, it's far too early to judge super PACs' influence because many of these outside groups have not yet begun to spend the tens of millions of dollars they've already raised in preparation for the fight ahead.

In the case of Wisconsin Gov. Scott Walker, the media has largely focused on how his Unintimidated PAC appears to have failed, pointing out that while deep-pocketed outside groups can provide a boost in advertising, they cannot legally help with some of the most basic functions needed to keep a campaign functioning. As the New York Times reported, “Super PACs, Mr. Walker learned, cannot pay rent, phone bills, salaries, airfares or ballot access fees.” Political reporters pointed out that even the Walker PAC's success in raising over $20 million couldn't prevent its candidate's eventual withdrawal from the race.

While super PACs certainly have their limitations, it would be naive to take Scott Walker's or Rick Perry's withdrawal from the presidential race as a sign that PACs won't have a significant impact on the 2016 election.

Last spring, the billionaire Koch brothers named Scott Walker to their short list of candidates in line for their support -- an expected endorsement of sorts that confirmed the financial force analysts expected Walker to marshal in the primaries. The Kochs spent roughly $400 million on the 2012 election and plan to spend hundreds of millions more in support of their handpicked candidate in 2016.

Walker's Unitimidated PAC already had several major donors.* But it had yet to begin to flex its financial muscles when apparent campaign mismanagement brought down the governor's bid. A comparison of how much both Walker and Jeb Bush's PACs have raised versus how much they have spent so far, as illustrated by OpenSecrets.org below, indicates the tsunami of spending yet to come:

Predictably, and necessarily, super PAC spending spikes as Election Day approaches. For those candidates who can competently manage their campaigns through the heavy advertising season, their PAC's ability to raise and spend millions on air time will prove invaluable. While super PACs may not seem relevant this fall, if the past spending patterns by outside groups documented by The Washington Post below is any indication, next fall's super PAC spending will be obvious when political campaign advertising goes into overdrive.

CORRECTION: A previous version of this post incorrectly claimed that the Koch brothers had donated to Scott Walker's Unitimidated PAC. Media Matters regrets the error.