AP:

The U.S. Supreme Court’s Citizens United ruling, which allowed unlimited corporate and union election spending, is now being used six years later to fight state limits on how much money individuals and groups can contribute directly to candidates.

Lawsuits against contribution caps have been filed in Alaska, Montana and New Mexico. Those challenges are being buoyed by a federal appeals court ruling last year that cites Citizens United in making it more difficult for states to justify donation limits.

“Contribution limits throughout the country are very vulnerable now,” said James Bopp, an Indiana attorney who is leading two of the lawsuits. “It’s going to be tough for any state to justify their limits under that standard.”

Ultimately, this question will depend upon who fills Justice Scalia’s seat (and other opening seats) on the Supreme Court. The stakes are as high as the Montana sky.