I’ve always thought the fear, ramped up by the Obama campaign, that shadowy interests would pummel them with advertising during the Presidential election, was unfounded. Shadowy interests may be shadowy, but they’re not stupid. They know the way to maximize their dollars, and it isn’t in the Presidential election. The top-line candidates are too well-known, and opinions too firm, for big money to make much of a difference one way or the other. Anyway, Obama and the DNC have a war chest that will easily counter any outside spending on the Presidential race.

It’s always been the downballot races that are at risk to a spending surge. We saw this in 2010, when all kinds of money flowed into Congressional and state lesiglative races late in the game, often determining the outcome. Those candidates are not well-known and can easily be defined by a flood of negative ads. We’re already seeing this happen in 2012, where it will almost certainly take place at a larger scale than the test run two years ago.

Outside groups, including super PACs and advocacy organizations, have spent at least $7 million on House races and $12.4 million on Senate races since the beginning of April, the first wave in what is expected to be a flood of independent spending this year in the battle for control of Congress.

Some groups, like the Club for Growth and FreedomWorks for America, which push for lower taxes and reduced government spending, spent heavily in primary races between incumbent Republicans and challengers in Utah and Indiana.

Democratic-leaning outside groups also spent money but appeared to be operating at a serious cash disadvantage. House Majority PAC, which seeks to help Democrats reclaim control of the House, had spent $234,000 since March on advertising in a special election in Arizona, where the party hopes to hold on to the seat that Gabrielle Giffords gave up, and $417,000 on a race for an open seat in California.

Considering that two years ago, there was virtually no outside money on the Democratic side, even the miniscule amount creates a bit more equity. But it’s not going to be enough. We recently learned that the Koch Brothers steered $55 million to front groups in 2010 to elect Republicans to Congress. I wouldn’t be surprised if that number doubled this time around.

So fretting about Super PACs in the Presidential race seems like a completely misplaced fear. The big money knows that the more obscure the seat, the bigger the impact they can have. And a lot of little seats add up to one big Congress owned by big money.