I'm a Catholic who supports getting rid of the marriage license. The government has no right to be the gatekeeper for the Sacrament of Matrimony. That's the Church's job.
As for non-catholics, they should be able to do whatever they want as far as the law is concerned.
What about all the legal stuff associated with state-recognized marriage, though? That's the drive for legalization of same-sex marriage, not that religious horse-sh*t. Why can't religious people separate in their mind the concepts of marriage recognized by the state for legal purposes and marriage within their own religion?