Six Republicans etched their names onto the wrong side of history Thursday night when they killed a bill that would have allowed for civil unions in Colorado.

In not too many years, Coloradans will look back and wonder how, in 2011, we could deny certain rights to our fellow Coloradans just because they happened to be gay. It will be similar to how many people look back to the 1960s and wonder how it was possible that states had laws to prevent blacks and whites from marrying each other.

It was wrong then, and it’s wrong now.

Yet Thursday, a few Republicans chose to keep Colorado from walking forward with other states that have recognized that gay citizens, and their children, deserve the same legal protections the rest of us enjoy.

“What makes me saddest,” said Rep. Mark Ferrandino, D-Denver, the bill’s House sponsor, “is there were people on that committee who were, I think, supportive in their hearts but weren’t willing to stand up against the leadership and the far-right fringe of their party.”

Civil unions — and we’ll go a step further and say gay marriage — are about equality, and their time is coming. The tide of public opinion is turning, and it’s turning quickly.

A Washington Post-ABC News poll released just last week shows a majority of Americans now support gay marriage. Fifty-three percent of those surveyed said gay marriage should be legal — the first time a majority has backed gay marriage in that particular survey. Other polls echo those findings.

Back in 2006, when Coloradans voted against Referendum I, which would have created civil unions in this state, only 32 percent of Americans supported gay marriage.

That’s a monumental shift in public opinion in such a short span of time.

Senate Bill 172 would have conferred a variety of rights to those engaged in a civil union, including the ability to inherit property if the other person dies, and the ability to make medical decisions if one person in the relationship is incapacitated.

Bottom line: It would have protected families, which ought to be considered a Colorado value.

We consider relationship equality to be one of the most important civil rights issues of our time. Even though we acknowledge that allowing gay and lesbian couples to legally marry will remain a contentious issue in some circles for years, we see few reasons not to allow civil unions.

While we were pleased that most of the debate at the statehouse over this issue was civil, at least when it came to lawmakers, we can’t help but be disappointed at the end result.

We thought the measure deserved to be debated on the House floor by 65 representatives. And we’re disappointed that gays and lesbians must wait, again, until they are recognized as equals in the eyes of Colorado law.

But the day will come. And still we’ll remember who was on the wrong side of history. Not with anger or vengeance, but with sadness.

As a state, we’re better than this.