"These people are getting to pay less by having their 'marriage' recognized by the USA. That means my taxes have to go up!!!111"
Something like that.
Not saying it's a good argument, and I'm not saying that MM would use that language, just relaying what I think MM is getting at. So, if things are zero-sum (which I don't think they are), then wide recognition of gay marriages could affect the tax base.
taxes *should* go up (imNSho) for *all* co-habitational romantic relationships without regard to whether they are "marriages". And I don't give a tinker's damn if they're same-sex or different-sex arrangements. ;0)
Any opinions expressed by me are mine alone, posted from my home computer, on my own time as a free American and do not reflect the opinions of any person or company that I have had professional relations with in the past 58 years. meep