Wealthy donors will be able to give more money to Minnesota candidates this year after a federal judge on Monday ordered a temporary halt to enforcement of the state's long-standing limit on certain political donations.

The decision from U.S. District Judge Donovan Frank draws heavily on recent U.S. Supreme Court opinions that have opened a flood of money into politics. Frank, with some clear personal hesitation, said he had no choice but to temporarily block enforcement of the Minnesota limit.

"Although the undersigned may not agree with the (U.S.) Supreme Court's recent line of cases on the subject of campaign finance and their effect on the integrity of public governmental institutions, the Court acknowledges that it is nevertheless bound by the decisions of the Supreme Court," Frank wrote.

The decision is only a preliminary injunction, while the case wends its way through the courts. But its results are immediate.

Minnesota's 20-year-old law was designed to limit the influence of big donors, lobbyists, political parties and political action committees, restricting the total amounts candidates could accept from those four special sources. Once candidates had gotten 20 percent of campaign donations from those sources, they could accept only half as much money from future individual big donors and no money at all from political parties, PACs or lobbyists.

Frank's decision lifts the limit on individual donors only. The limit on political fund, PAC and lobbyist giving remains intact.

Opponents of restrictions on campaign finance predicted the ruling would be the first of many.

"There is a wide variety of campaign finance laws at the state level, many of which pose exactly the same constitutional problems as the federal campaign finance laws. I think we are going to see a lot of litigation trying to clear up the constitutionality of those laws and to get them off the books," said Paul Sherman, senior attorney for the Institute for Justice in Virginia. The Institute brought the Minnesota lawsuit on behalf of two donors, a candidate and Republican state Rep. Linda Runbeck.

"The state of Minnesota cannot dish out First Amendment rights on a first-come first-serve basis," said Lee McGrath, executive director of the Institute for Justice Minnesota chapter.

Rep. Ryan Winkler, DFL-Golden Valley, who has fought for greater disclosure of campaign spending, decried the ruling.

"It is another way for very rich individuals to have even greater influence in the political process. It makes a bad situation worse," Winkler said.

Sea change in finance

Restrictions on campaign giving and spending have been falling ever since 2010, when the U.S. Supreme Court decided in the sweeping Citizens United ruling that government cannot bar corporations and labor unions from independent political spending.

Last month, the high court ruled that aggregate limits on how much individuals can give to federal candidates, PACs and parties were unconstitutional.

The Supreme Court decisions sent shock waves through political circles and ushered in an age of vastly greater spending on political causes. Frank's decision, while narrower, continues to clamp down on government's ability to restrict political donations. It is one of the first state-level rulings that rest on the most recent Supreme Court decision, but it is unlikely to be the last.

The state law would have limited this year's gubernatorial candidates to accepting only $730,200 from those four special sources. Before they hit that limit, candidates could accept up to $4,000 from any individual. After the candidates hit the $730,200 limit, they could accept only $2,000 in contributions per individual and they cannot take any money from lobbyists, political funds and PACs.

For House candidates, the limits are much lower. House candidates could accept up to $1,000 in donations from individuals, lobbyists, political funds and PACs. But once they hit a collective total of $12,500, no individual could give more than $500.

After Frank's decision on Monday, a gubernatorial candidate can accept $4,000 all the way through their campaigns and House candidates can take up to $1,000, no matter how much they've previously received from lobbyists, PACs, political funds or large-dollar donors.

The state will have at least a month to decide whether to appeal the decision. Gary Goldsmith, executive director of the Minnesota Campaign Finance and Public Disclosure Board, said Monday that it was "far too soon to determine" what course of action the board will take. He said the state is restrained from limiting how much later donors can give. He said the agency will spread the word to parties and through its e-mail list.

Rachel E. Stassen-Berger • @RachelSB