Although U.S. District Court Judge Roslyn Silver issued a tentative ruling on January 15 in the Arizona public funding lawsuit, suggesting that part of the program is unconstitutional, she still has not decided on just how much of the program should be invalidated. See this story.

Generally, she feels that the part of the program that gives extra public funding to candidates who have opponents who aren’t using the program but who raise a great deal of money cannot survive. But, as the story indicates, she hasn’t decided whether the extra public funding is untenable for publicly funded candidates who have opponents who get their private money from other donors, or whether the extra public funding is only untenable for publicly funded candidates who have opponents who fund their campaigns with their own money.

Her decision is based on the U.S. Supreme Court ruling Davis v Federal Election Commission, which invalidated the “millionaire’s amendment” portion of the McCain-Feingold law. The McCain-Feingold law has nothing to do with public funding of campaigns. But the McCain-Feingold law did have a provision that said when a candidate for Congress has a very wealthy opponent who is self-financing his or her own campaign, then opponents of that wealthy candidate got an exemption from worrying about the normal limits on contributions made to them. The U.S. Supreme Court said the special treatment for candidates who have wealthy opponents is unconstitutional. The Court felt, once Congress has set limits on how much individuals can contribute, it must stick to the principle that the limits apply equally for all candidates, whether they have wealthy opponents or not.

So, by analogy, Davis v FEC seems to mean that public funding programs themselves are constitutional. But provisions of public funding programs that give large amounts of extra public funding to candidates who have well-funded opponents are not constitutional. However, if the Arizona decision is based on Davis v FEC, it is not clear whether the extra public funding should be thrown out entirely, or just for publicly funded candidates who have wealthy self-funded opponents (as opposed to candidates who have opponents who are very successful at raising private contributions).