Why would same-sex couples need their marriage to be accepted legally in all states? The same-sex couple would not be able to move within the United States and keep their legal marital status. It would encourage other states to discriminate against them when traveling. If they moved to a state that did not recognize their marriage, their children may not be able to attend their local public schools and would have to attend a private school. If they had children, they would have to live in a state where same-sex marriage was legal.