Super PACs and wealthy donors will pour hundreds of millions of dollars into the presidential election, and most of it will come to the aid of Mitt Romney. This has left some liberals in a state of near-panic, worried that the flood of money will depress President Obama’s approval rating among undecided voters, and keep him from winning in critical toss-up states like Colorado, Florida and Ohio.

But there are two important things to remember when thinking about Super PAC money. First, there is a diminishing marginal return to campaign ads — the more you saturate the airwaves, the less effective advertising becomes.

The second point is a little less polite: Rich donors just aren’t as sophisticated as you might think. Buzzfeed has a good piece on the political incompetence of the people who fund Super PAC expenditures:

The secret story of political money has always been the disdain with which much of the political class views donors: They are meddlers and dilettantes, full of terrible advice and inane questions. And donors are justifying that disdain in 2012 as never before. The casino magnate Sheldon Adelson, by far the worst of this cycle’s political investors, put $10 million behind Newt Gingrich after he had effectively lost the primary campaign.

Other groups have poured millions into states their party is unlikely to contest — like Pennsylvania. And perhaps worst of all, their messages often have more to do with donors’ priorities than with a winning ticket. The Koch-backed Americans for Prosperity has drawn particular grumbling for ads whose goal, critics say, is more about ideology than victory in November, its daily message determined, one rival SuperPAC operative jabbed, by “whatever the Koch brothers had for breakfast.”

These people have tens of millions of dollars to spend, but there’s no guarantee that they have any sense of what makes a campaign effective, or what kind of ads would work best against a candidate who is familiar to nearly 100 percent of Americans. What’s more, they don’t have the capacity to run a ground operation, and because they can’t coordinate with the campaigns, they can’t tailor their message to what Team Romney wants. To a large degree, they are political berserkers — organizations of tremendous, unfocused power. For a presidential race — where both sides are near-parity and targeting is everything — this is of limited utility.

As always, of course, there’s a big caveat. Super PACs might be of limited utility in presidential contests, but they could be decisive in downticket races. Given the smaller sums involved— and the smaller odds that a challenger will be recognized by voters — a Super PAC has the potential to change the dynamics of a Senate, House or statehouse race. Which is why liberals should worry less about what Karl Rove might do in the presidential race, and far more about his promise to drop millions into congressional races around the country. Barack Obama will be fine. Chris Murphy, on the other hand, is vulnerable.

Jamelle Bouie is a staff writer at The American Prospect. You can find his blog here.