Note that even if a bill is ever passed that the state would no longer allow formation of such marriages within its borders, it would pass into law as of a certain date in the future vs. retroactively. If you'd entered into such a marriage before the effective date, you'd be okay. It won't be a situation where folks who agreed they were married even a day before the law goes into effect are now suddenly deemed unmarried.
Woe would be unto the spouse seeking a divorce down the road who didn't keep careful track of the date they agreed to become man and wife in the event such a law is passed and his-her spouse wanted to dispute when they entered into that agreement, arguing it came *after* the law was in effect and therefor there was no lawful marriage formed (though obviously that allegation might be countered by other evidence).
Kinda why I'd want something in writing signed by the parties acknowledging that they agreed they were man and wife as of a particular date vs. necessarily having to rely only on evidence like witness testimony, joint tax returns being filed, etc.