omit the term marriage from all government use.

The United States government, state, and local governments should stop using the term marriage. Marriage was created as a religious ceremony, and only religious entities should be entitled to perform or dictate marriage under their own provisions. The government should change the terms from marriage to civil unions, legally bonded cohabitants or any other non religious terms they deem noteworthy.
This would cause less friction between opposing views. Also, the terms the government chooses would be appropriate for government use only ex. insurance, taxes, census, etc. Yet it would allow religious entities to perform the actual marriages to that entities digression.