Presidential hopeful Mitt Romney has said that unrestricted super PACs are a “disaster” and should “disappear” — including the one that’s spent close to $8 million pummeling his GOP primary opponents.

But his solution — to toss out federal contribution limits so candidates, too, can raise unlimited cash — has only intensified the controversy over the pro-Romney Restore Our Future political action committee and the future of campaign financing.

The former Massachusetts governor has put his finger on the key question hanging over the two-year anniversary of the landmark Citizens United ruling to deregulate campaign spending. That is, how long can the few remaining election laws withstand the tide of big money, ushering in a system of total deregulation?

Reform advocates argue that voters want strict new rules, not more big spending, and have organized hundreds of protests in the coming days to call for a constitutional amendment that would reverse Citizens United v. Federal Election Commission, decided on Jan. 21, 2010. They point to the Occupy Wall Street movement as evidence that Americans are eager for fresh curbs on corporate political influence.

“I believe that the American people are outraged by what they properly perceive to be the corporate capture of Washington,” said Robert Weissman, president of Public Citizen, which has helped stage the protests.

But Weissman acknowledged that Romney isn’t the only one attacking contribution limits. Indeed, First Amendment champions are well into a methodical legal campaign to challenge the constitutionality of limits on contributions to political candidates and parties. Now that outside groups can raise and spend unrestricted money, they argue, candidates and parties should be free to compete on the same terms.

In election law circles, all eyes are on United States v. Danielczyk, a lower court case that challenges the existing ban on direct federal contributions to candidates. It’s one of dozens of lawsuits assailing both disclosure laws and contribution limits at the state level. If the Danielczyk case makes its way to the high court, Romney’s theory that candidates should be free to raise big money outside the rules will be put to the test.

“Whether or not the court will have the appetite to take [up] that issue is the biggest unanswered question right now in campaign finance jurisprudence,” said Richard Hasen, a political science and law professor at the University of California, Irvine. If the Supreme Court sides with the challengers, it would topple a federal ban on direct corporate contributions that dates to 1907.

The Republican National Committee recently filed an amicus brief in the Danielczyk case, arguing that under the current system, which at least in the primaries has been dominated by super PACs, “traditional political parties and candidate committees are in danger of having their voices drowned out.”

Some argue that super PACs have already eviscerated the contribution limits. In Citizens United, the Supreme Court ushered in the PACs by ruling that outside players may raise unrestricted corporate and union money as long as they operate independently from candidates and parties. Yet the top presidential super PACs are staffed by the former aides, colleagues and political advisers of the candidates, note watchdogs who argue that super PACs are hardly independent.

But the high court stopped short of tossing out the long-standing limits on donations to parties and candidates. That’s a key distinction that keeps candidates one step removed from the multimillion-dollar corporate checks underwriting super PACs. The limit on what an individual may give a candidate still stands at $2,500 per election, for example.

“Whatever the problems are with super PACs, and they are very serious, those problems would become far worse if we removed the contribution limits,” said Fred Wertheimer, president of Democracy 21. The Supreme Court’s 1976 Buckley v. Valeo ruling, enacted in the wake of the Watergate scandal, clearly established the potentially corrupting influence of unrestricted donations, he noted.

A ruling to throw out the contribution limits “is one that raises the specter of real corruption in a way that we haven’t seen since before Watergate,” Hasen said. “At least now you don’t have millions of dollars going directly into candidate campaign coffers.”

Surprisingly, some reform advocates are also taking direct aim at the Buckley ruling, which equated money with speech. The Buckley court upheld limits on what individuals could donate to candidates, but it threw out the post-Watergate limits on political expenditures, ruling that they violated the First Amendment. Reform advocates now pushing for a constitutional amendment argue that it should include a provision to establish spending limits on campaigns. It’s an ambitious strategy, at best.

“These amendments dramatically overreach and haven’t really thought through very well what their consequences would be,” said Brad Smith, chairman of the Center for Competitive Politics. Smith’s group has filed a brief siding with  the RNC in the Danielczyk case.

More realistic are pending Congressional proposals to revive some form of disclosure legislation, which Democrats failed to push through the previous Congress, and to impose new limits on coordination between candidates and super PACs. In the meantime, expect more politicians to join Romney in agitating for the same wide-open playing field that super PACs enjoy.

For candidates, “the incentive is going to be there to liberalize your own ability to raise money quickly, easily, without having to jump through too many hoops,” Smith said. “Pretty soon, it’s going to be clear that that’s the way that we’re going to have to go.”