How something is described often affects how people react to it. So it's interesting, as the Supreme Court begins two days of arguments on how to and who can define marriage, to see how the lawmakers across the street have talked about the same issue.

A look through Sunlight's Capitol Words shows a clear partisan divide: Democrats tend to use the term "gay marriage" while Republicans prefer "same-sex marriage."  As you can see in the chart above, the latter term occurs more frequently in congressional debate. The full Capitol Words analysis gives us the party breakdown: Democrats account for 73 percent of the utterances of the term "gay marriage," while Republicans account for 62 percent of the useage of "same-sex marriage."

A graph of the usage of the term "gay marriage" shows big spikes during the summers of 2004 and 2006.

In both instances, Congress was debating whether to amend the Constitution to define marriage as being exclusively between a man and a women. The last time the House voted on the measure, it failed to win the two-thirds majority required to move a constitutional amendment towards ratification.

Among lawmakers who use the term "gay marriage" most frequently, according to Capitol Words, most are Democrats who favor the concept, including Sen. Barbara Boxer, whose state of California is the central actor in the case the Supreme Court is hearing Tuesday, and Senate Majority Leader Harry Reid of Nevada. But the list also includes Sen. James Inhofe, an Oklahoma Republican who is a staunch opponent of same-sex unions.