That is Republican state Representative Maureen Walsh of the state of Washington. Walsh is speaking out in favor of legislation that will legalize same-sex marriage. It passed both the House and Senate, and will be signed by Democratic Governor Chris Gregoire. Interesting note: Governor Gregoire was not originally a supporter of marriage equality.
I know some of my activist friends in the LGBT equality movement wish change would happen quicker. I do too. But change doesn't often come as a tidal wave. It's more of a slow movement. And occasionally, you can capture an individual changing, such as in this very moving video from Representative Walsh.