A reader writes with the following hypothetical:

It was my thinking …that there would actually be a legitimate case against applying the initiative retroactively for this reason: As a voter, I would walk into my polling place not knowing the manner in which my vote will be counted. Let’s say I truly support Nader, but want to vote strategically. I could reasonably feel that in an all-or-nothing system I would vote for Kerry, whereas in a proportional system (since the consequences of a Bush victory in CO are much less with respect to the electoral college) I would vote for Nader. Does this not present a constitutional problem?

Good point I’ll have to ponder this some more, but at first blush this seems like a more plausible claim than a claim based simply on unfair surprise.