Openly gay state Senator Pat Steadman, a Denver Democrat, will introduce a bill in the upcoming legislative session that would make Colorado the fourth state in the country to recognize civil unions between two people of the same gender. Steadman says many of his constituents support the idea. “They think we have really progressed in our attitude toward gay and lesbian couples and our recognition that current law discriminates against them and disadvantages them,” he tells The Denver Post.

The news has already set off alarms among Christian conservatives. Citizen Link, which is affiliated with the evangelical Focus on the Family in Colorado Springs, opposes the proposal. “We could not support a law that undermines marriage, and that’s exactly what civil unions do,” says Citizen Link’s Jenny Tyree. “I think that kind of bill would be of concern with the vast majority of the members of our caucus,” claims state House Speaker-elect Frank McNulty, a Republican from Highlands Ranch. But Representative Kevin Priola, a Republican from Henderson who will become speaker pro-tem next year, supports civil unions “in concept, precisely because they are not gay marriage.”

Some of the state’s big political funders, however, endorse the idea, such as Colorado millionaire Tim Gill, who has funneled campaign donations elsewhere to support gay civil unions, as well as marriage, reports Politico. “We’re at a point of time where the national conversation around marriage in a lot of states has moved to a point where it’s no longer acceptable to not be there,” says Bill Smith, the deputy executive director of the Gill Action Fund, the donor’s political arm.

Meanwhile, the French system of civil unions, created in 1999, provides an interesting lesson about modern life. There, civil unions aren’t just for same-gender couples. In fact, the overwhelming majority of civil unions in France are among straight couples, who see the process as a step of togetherness slightly less formal than marriage, writes The New York Times.