Public Advocate used the photo, which had been posted on the couple’s blog, twice, the suit alleges. In the spring, it sent out a mailer against State Senator Jean White, a Republican who has supported civil unions for gay couples, with the couple’s photo and the words “State Senator Jean White’s Idea of ‘Family Values?’” written across it.

Public Advocate sent a similar mailing in opposition to Jeffrey Hare, a Republican candidate for the state House of Representatives. For this mailing, the couple appeared to be performing their kiss in an open field against a cloud-dotted sky. “Jeffrey Hare’s vision for Weld County?” read the copy. Mr. Hare, too, was defeated in the primary.

The suit (see complaint), filed by the Southern Poverty Law Center, which advocates for gay rights, among other things, seeks unspecified damages.