"I don't go down to tell them what to do, I expect them not to come up to Alaska and tell us what to do," said one person featured in the ad.

Democrats, armed with reams of poll data, argue that voters don't like interference in their elections from well-heeled outside forces. They're not wrong. Broadly speaking, voters are wary about enormous sums of cash in politics, and it's easy to turn people against outsiders.

But that argument might be beside the point. Voters don't like the outside interference, but their distaste doesn't necessarily have the resonance to push voters away from the GOP. And even for all of the influence wielded by Americans for Prosperity and other Koch-affiliated enterprises, they're still just outside groups in an election in which voters are still just choosing between Republicans and Democrats.

"There's a trap in campaigns that's called the Other People's Money trap," said Brad Todd, a Republican strategist. "Voters care about their money, not other people's money. Anytime my candidate is talking about the voters' money and my opponent is talking about other people's money, I feel pretty good about our chances."

It gets trickier for Democrats in individual races. Along with Begich, Senators Mark Pryor in Arkansas and Mary Landrieu in Louisiana each accepted money from the Koch Industries PAC in recent years. Blasting them now—all three are battleground races this year—risks making the incumbent look like a hypocrite.

And in Georgia, where Democrats have high hopes that Michelle Nunn can pull off an unexpected victory despite the hostile territory, the party must grapple with the presence of the Koch-owned Georgia-Pacific. The company, which makes a variety of products, employs thousands of people in the Peach State. Republicans have already signaled that if Nunn's campaign attacks the Koch brothers, they'll be ready to hit back by suggesting she's threatening the business interest of her home state.

The strategy isn't all downside for Democrats: Although most citizens may not know who the Kochs are, liberal activists certainly do—including the wealthy ones, from whom the Democrats are desperately trying to coax the kind of large donations that will let them push back more forcefully in TV ads. And the Kochs do complicate the GOP's own political efforts, too, as when their company closed down a small plant in Alaska. It wasn't a game-changer for the Alaska race, but it did allow Democrats to blast the GOP field's ties to the brothers.

But those efforts are about mitigating the damage done by the AFP's ads, and not necessarily a way to start scoring points of their own. For that, the party might need to turn elsewhere.

"Right now, Democrats can't figure out how to get away from Obamacare, so they are digging around desperately for something off-topic to discuss," Todd said. "I had the same emotion in 2006 when it was obvious the war was going to beat us but we weren't willing to run against the war that we believed in. There is never any magic trick to get out of this box when your party is on the wrong side of the only issue voters care about."

We want to hear what you think about this article. Submit a letter to the editor or write to letters@theatlantic.com.