That's been their overt strategy for the last 20 years. They've had 600 gay lawyers working on this for longer than that.
The Gay Manifesto of 1972 listed gay marriage as one of their goals. So that’s 37 years at least that gay activists have been dreaming of the day when homosexual marriage is the law of the land. Then their lives will be complete, if you can believe the rhetoric.
In reality, their lives won’t be complete then. If they achieve this goal, they will simply move on to the next items on their grievance list.