Since the Supreme Court decided earlier this year that corporations have a First Amendment right to spend however much they like to influence elections, groups have been attempting to use that decision to hack away at the core of federal and state campaign finance laws.

Last month, the Supreme Court declined to hear a challenge to the federal ban on soft money (unlimited contributions to political parties), a centerpiece of the 2002 McCain-Feingold campaign reform bill. Though that case was cut short, at least one other challenge to the law is in the works.

Now, groups at the state level are trying to use the Citizens United decision as leverage to do away with bans not only on independent expenditures by corporations, but also on corporate contributions directly to candidates’ bank accounts. 22 states, like the federal government, prohibit corporations from contributing directly to campaign committees. After Citizens United, business groups in Montana were the first out of the gates, filing suit to get rid of Montana’s 98-year old ban on both independent campaign expenditures by corporations (the spending that Citizens United allowed on the federal level) and direct corporate contributions to campaigns (which Citizens United didn’t touch).

In May, the Minnesota Chamber of Commerce convinced a federal court to strike down that state’s independent expenditures ban. Now, Minnesota business interests are following the Montanans’ lead and broadening their challenge to include the state’s ban on direct contributions:

State law now allows corporations to spend money independently of campaigns on ads supporting or opposing candidates, an arrangement that the U.S. Supreme Court approved early this year.

But the Taxpayers League of Minnesota, Minnesota Citizens Concerned for Life and Coastal Travel Enterprises seek to go beyond that ruling and allow direct contributions to candidates by corporations.

"Our clients believe … that the First Amendment gives corporations … the right to contribute to candidates and political parties through their general treasury funds," said Joe La Rue, an attorney for the plaintiffs, who sued this week in U.S. District Court in Minnesota.

In Citizens United, the Supreme Court clearly created a slippery slope of corporate money in politics. State-level bans on independent spending by corporations have been the first to go. Will guards against corporate-to-candidate contributions—and the very clear appearance of corruption that they create—be next