Trevor Potter, Stephen Colbert's lawyer, predicts an expanded role for the organizations.

Despite mixed results this cycle, super PACs and other outside fundraising groups aren't going anywhere. In fact, they're settling in for the long haul.

"I think we're just beginning to see the influence of super PACs and their nonprofit affiliates, and how that plays out," said Trevor Potter, a Washington lawyer perhaps best known as the legal counsel to comedian Stephen Colbert's super PAC. Potter spoke at The Atlantic's Washington Ideas Forum.

More than $1 billion was spent by outside groups this cycle. Republican-leaning groups, in particular, spent millions on races that went nowhere -- most notably Mitt Romney's presidential bid. But a poor track record isn't going to turn either Democrats or Republicans away from the funding mechanisms, and it's not going to turn off donors, Potter said.

It just doesn't make sense to risk being out-raised by the other guy. Aggressive fundraising by candidates up and down the ballot, and the fear of being vulnerable to super PAC spending from the other side, is the new normal.

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So is misleading advertising.

Pro-Obama group Priorities USA Action ran an ad this cycle that implied that actions by Bain Capital, the private equity company Romney founded, indirectly led to a woman's death. Asked about the ad, which was widely criticized as untruthful, Priorities USA and Priorities USA Action senior strategist Bill Burton quipped: "I would say misleading more than inaccurate." What the group was trying to say with the ad, Burton said, is that Bain's actions had "real life consequences."

The ad kept pundits talking about Romney's private equity career for a full week, Burton said. "We may have taken a lot of heat" over the ad, but "it didn't accrue to the president," he said. And it didn't improve people's opinion of Romney's business background.

Unlike a candidate, super PACs aren't accountable to voters, or to a party. They're not really accountable to anyone. They can run ads candidates don't dare to run, Potter said: negative ads, misleading ads, ads that deviate from a candidate's core message or that even run counter to a candidate's core message.

There is room for regulation that could somewhat tame the post-Citizens United landscape. Courts would likely allow regulations that forced groups to disclose their donors, prevented candidates from attending events on their behalf, or prevented campaign aides from creating such groups, Potter suggested.

And after the election? Burton indicated that it didn't really make sense to disband Priorities USA and Priorities USA Action, not while Karl Rove's American Crossroads is still raising money for Republicans.

The next phase for super PACs is to "turn into lobbying organizations," Potter said. Why not? They have a staff, a brand, and if they're a group -- or have an arm -- that's registered as a nonprofit, they have to lobby in order to keep their IRS status.