A bill to allow same-sex couples to form civil unions died on the calendar late Tuesday, taking down more than 30 other measures with it in a dramatic game of political chicken in which no one would blink.

When Republican Speaker Frank McNulty acknowledged there was an impasse and abruptly ended his news conference on the House floor, Coloradans watching in the gallery started chanting: “Shame on you! Shame on you!”

Everyone was kicked out of the gallery after someone yelled, “I hope you (expletive) die!”

The stunning turn of events on the second-to-last day of the 2012 session had been brewing since Thursday, when a Republican lawmaker voted with Democrats to pass the civil unions bill out of committee.

Social conservatives who believed the bill would die in the GOP-controlled Judiciary Committee for the second year in a row were enraged and lobbied McNulty and House Majority Leader Amy Stephens to use every procedure to kill Senate Bill 2.

That’s exactly what happened, but in the process of making sure civil unions died on the calendar, a slew of other bills became casualties too.

Among the bills ensnared in the tug-of-war in the House: $20 million worth of water projects statewide and a bill that sets a standard for driving while stoned.

Throughout the evening, Gov. John Hickenlooper, a Democrat and a supporter of gay rights, worked with legislative leaders to try to break the impasse, briefly meeting with McNulty outside the speaker’s office.

At another point, Republican Mark Waller of Colorado Springs and Democrat Mark Ferrandino held dueling news conferences on the House floor.

Longtime veterans of Capitol politics could not remember a more suspenseful end to a session, which by law must end at midnight tonight.

Waller, the assistant majority leader, blamed Senate Democrats for the clock running out, saying they held onto the bill for months before sending it to the House on April 27.

“Let’s be clear: The Democrats in the state House are playing procedural games to have one heard over every other bill,” he said. “We need to carefully consider what’s before us right now. Careful consideration means taking time.”

Waller refused to respond to questions about why Republicans were filibustering, including debating a bill on trans-fats in school lunchrooms in excruciating and sometimes hilarious fashion.

Rep. David Balmer, R-Centennial, practically screamed as he pounded on the lectern.

“Not a one of you has the courage to vote against chocolate!” he said.

The civil unions bill had to be debated Tuesday in order to qualify for a vote today on the final day of the session.

Ferrandino, the minority leader, argued that the House has managed to hear plenty of other bills in recent days. At least five Republicans have publicly said they support the measure, meaning that if it would have been heard, it would have passed.

Sen. Pat Steadman, D-Denver, said the bill was heard late because the speaker pro tem, Rep. Kevin Priola, R-Henderson, was considering sponsoring the bill and asked him to wait until after the GOP state convention in mid-April. Priola said he wanted to make sure he didn’t have a primary opponent. Although Priola supports the bill, he did not sign on as the House sponsor, a role Ferrandino accepted.

Priola said he talked to Steadman about the difficulty of Republicans in a primary supporting the bill.

“They have done this to themselves,” Steadman said. “They have brought dishonor and ill repute to the House. They ought to be ashamed.”

The fate of a civil unions bill has dominated the session ever since it passed the House Judiciary Committee last week with the support of Rep. B.J. Nikkel, R-Loveland, who enraged social conservatives with her vote.

Supporters of civil unions rallied Tuesday outside the Capitol.

“No matter what happens today or tomorrow, the unspoken truth in this whole debate is we will win,” Jace Woodrum, deputy director for One Colorado, the state’s largest gay-rights group.

“Whether it is today or tomorrow or next year or the next, we will win. Gay and lesbian couples in this state will have full protection under the law. We all know it, and everybody in this building knows it,” he said.

The bill passed the House Appropriations Committee on Tuesday afternoon after a brief walkout by some Democrats, who questioned why the committee was hearing House bills that had no chance of getting to the Senate in time.

As expected, Rep. Cheri Gerou, R-Evergreen, voted for the measure, despite pressure from some Jefferson County Republicans to vote against the bill.

At the rally, Sen. Mike Johnston, D-Denver, debunked as myth the theory Republicans didn’t have time to pass civil unions.

“What is in question is not time,” he said, “but courage.”

Lynn Bartels: 303-954-5327 or lbartels@denverpost.com