We have ID cards in Massachusetts, you can get one of those without needing to take the driving exam. There is a "LiquorID" card that lasts five years, I can't find any information on the "MassID" card but it's probably good for five years as well.

Thank you for asking the question, I had assumed these cards lasted as long as a driver's license and that is not the case. :-)

You make a good point in that these voter ID cards might have a longer expiration then a driver's license. To my knowledge the expiration period of the ID isn't a part of the legislation. In that case we can probably expect to see the length of time vary from state to state. In that case I would suspect that state's with a shorter valid period might be trying to manipulate the number of legal voters.