For a time, this home-town documentary by Mike Roth and John Henning seems as perfunctory as its title, something we already know about and applaud: the fight for gay marriage in Massachusetts. Why isn’t this on TV? But Roth and Henning, dedicated partisans, were everywhere with their cameras in those historic years 2003–2006. They were witnesses to dramatic moments of the gay-and-lesbian struggle that escaped our newspapers and newscasts, such as Dianne Wilkerson’s noblest hour, her speech in the legislature supporting gay matrimony. Saving Marriage branches out to the 2004 Democratic state-legislature primaries, where same-sex marriage was the salient issue and a bevy of Massachusetts local heroes like Barbara L’Italien and Kathy Teahan supported it at the risk of their jobs. The most emotional scene of all? At Cambridge City Hall on May 17, 2004, where crowds cheered each couple as gay marriage became legal for the first time anywhere in America. 90 minutes | Kendall Square