Updated at 12:02 p.m.: The Colorado Senate on Wednesday morning failed to pass a proposed child sexual abuse constitutional amendment. If ultimately approved by voters, the measure would have allowed the legislature to remove the statute of limitations on cases of child sexual abuse from years ago, allowing those victims to sue. The 23-12 vote fell along party lines and was one vote short of the two-thirds threshold needed to refer a constitutional amendment to the ballot.

The measure will not move on to the House.

In a statement after the vote, Senate Republican leaders said they were united against those who commit crimes against children but could not overcome their concerns with the amendment as drafted. If it passed, they said, the retroactive lifting of the statute of limitations for older crimes “would have upended numerous constitutional and legally settled rights we all depend on, including the principles of legal certainty and reliance, the principle of finality of litigation, and due process.”

Previous reporting: The Colorado Senate gave initial approval Tuesday to a constitutional amendment that seeks to ultimately allow victims of years-old child sexual abuse to file lawsuits against their abusers and the institutions that protected them.

But Republican opposition, which solidified in late February, still threatens to derail the effort before an expected final vote in the chamber this week.

The resolution, if approved by lawmakers and then by voters statewide in November, would amend the state constitution to allow legislators to remove the statute of limitations preventing victims from suing over abuse that happened years ago. The change would be needed because of a Colorado Supreme Court decision last summer that invalidated a state law allowing for retroactive abuse lawsuits.

The threshold to refer a constitutional amendment to the ballot is two-thirds in each legislative chamber — posing a major hurdle for Democrats. They have a large majority in the Senate, but they’re one seat shy of that threshold. Republican opposition repeatedly has delayed the resolution’s advancement and now threatens to sink it entirely.

Supporters held a news conference in the Capitol Tuesday to rally support for moving the measure on to the House. Among those on hand was Rachael Denhollander, a national advocate for victims who was the first of many gymnasts to report their sexual assaults at the hands of disgraced former U.S. gymnastics doctor Larry Nassar.

She described the need to hold institutions accountable.

“Access to the court system is the best chance anyone has at forcing institutions to take responsible, desperately needed, common-sense steps to protect the next generation,” Denhollander said. “Access to the court system is the only chance that survivors have for justice and for the help they desperately need.”

Later, on the Senate floor, the resolution’s backers said the amendment also would address other circumstances that often affect sex abuse survivors.

“The pain and trauma inflicted on victims of childhood sexual abuse is unique,” said Sen. Jessie Danielson, the Wheat Ridge Democrat sponsoring the bill with Sen. Rhonda Fields of Aurora. “Empirical evidence shows how survivors are unable to come forward to face their abusers until much later in life.”

With just over three weeks left in the legislative session, Danielson said the resolution needed to finally be put forward for a vote.

Senate Democrats sought to hammer home the importance of the resolution to skeptical Republicans: Danielson read testimony from abuse victims and said one was set to file a lawsuit but was blocked by the state Supreme Court. Sen. Dafna Michaelson Jenet, a Commerce City Democrat, described how she was abused as a child.

But Republican opposition — rooted in concerns about fading memories, constitutional rights and hefty future lawsuits against schools and churches — appears to have held firm.

Danielson said before Tuesday’s preliminary vote that no Republican had committed to supporting the measure. Two top Senate Republicans, Minority Leader Paul Lundeen and assistant minority leader Bob Gardner, told fellow legislators they remained opposed.

Republican Sen. Mark Baisley’s name is still listed as a co-sponsor of the resolution, but he previously said he no longer supports it.

Tuesday’s vote, which required just a simple majority, was taken by voice, and no Republican senator appeared to speak in support. A final vote in the Senate could come as early as Wednesday. If the resolution fails to clear the two-thirds threshold, it won’t advance.

“In some ways, this is the hardest vote of my legislative career,” Lundeen told fellow legislators. He said he was concerned about “miscarriages of justice” and institutions facing lawsuits for incidents from years ago. “… My vote is cast in defense of the constitutional and legal principles each and every one of us, and future generations as well, rely on for protection in our civil society.”

Various insurance groups and the Colorado Catholic Conference are opposed to the bill, and some school groups have expressed concerns.

But Fields said that institutions shouldn’t be able to sweep past abuse “under the carpet.”

“I don’t think they need special protection,” she said. “I want them exposed.”

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