Colorado State Senator Pat Steadman is sponsoring a bill that would give gay couples many of the same benefits and responsibilities of marriage.

Steadman, an openly gay Democrat, told the Colorado Independent that he's proposing the law because a constitutional amendment bans gay marriage in the state.

“Promoting a lesser status for gay people is not ideal,” he said, but added that in the short term “people could really benefit from civil unions.”

Over the last couple of years, Connecticut, New Hampshire and Vermont have scrapped their civil unions laws in favor of full marriage, leaving only New Jersey, which passed on the upgrade last year, to offer the union.

But civil unions have returned in a big way this year.

On Monday, Illinois Governor Pat Quinn signed a civil unions bill into law in front of a capacity crowd. And last week, a civil unions bill was approved by the Hawaii Senate.

Lawmakers in Wyoming and Maryland have also promised to introduce similar legislation.

Steadman said he's likely to introduce his bill over the summer. Representative Mark Ferrandino will sponsor the measure in the House.

A majority (52%) of Colorado residents favor legalizing gay marriage.