Can the gov't pass a law saying that only the first 12 people to vote in an election get to vote for every office, or that only the first 12 people who arrive at church get to stay for the entire sermon?
But that is exactly what Minnesota law does when it comes to contributions for state political candidates.
Contributing to candidates for political office is a well-recognized First Amendment right and that right cannot be dished out on a first-come, first-served basis.