Recognition of same-sex marriage and civil unions is as much an economic issue as a civil rights issue.
Federal recognition will allow same sex couples to file taxes jointly. It will allow them to avoid costly legal paperwork by giving partners legal standing even in states that do not offer same-sex marriage as an option.
Federal recognition would allow federal employees to list their same-sex spouses for survivorship benefits under social security and military retirement. It will allow federal employees to provide insurance benefits to their same-sex spouses and the children of their spouses, as well.