This is an archived article and the information in the article may be outdated. Please look at the time stamp on the story to see when it was last updated.

DENVER — Federal data Tuesday showing Colorado kindergartners having the lowest immunization rate in the country would seem to illustrate that parents here already have the option of not vaccinating their children against certain diseases.

But this week, just as a politically fraught debate over vaccinations is dominating the conversation between 2016 GOP presidential hopefuls, Colorado lawmakers will debate legislation that would underline the rights parents already possess to opt out of immunizations as well as comprehensive sex education in schools.

“We want to make sure that the choices that parents are already allowed are further stated by our bill,” said Sen. Tim Neville, the sponsor of Senate Bill 77, which would establish a Colorado “Parent’s Bill of Rights.”

To Neville, the idea, which came from hundreds of conversations he had with frustrated parents during his campaign last year, is based on a simple if old-fashioned premise: parents know best.

“As a parent, I probably know best  for my children,” he said. “I already have the responsibilty under law, I should make sure I have the right to make their decisions for their education, their moral upbringing and also to keep them safe with the medical decisions being made.”

But the proposal goes beyond underlining the existing rights of parents, authorizing Colorado parents to make all medical decisions for their children until they’re 18.

“It’s grandstanding,” said Sen. Irene Aguilar, D-Denver. “And it carries potentially serious consequences.”

Aguilar, the sponsor of the 2013 law mandating comprehensive sex education in Colorado schools (including an opt-out for dissenting parents) and a doctor of internal medicine, worries that the attempt to strengthen parents’ rights will undermine those of young people, who often aren’t comfortable discussing their physical and mental health issues with their parents.

“Perhaps the mental health problem is related to sexuality, they’re figuring out if they’re LGBT or something — for all we know, it’s related to abuse that’s happening in the home,” she said.  “I think for someone to admit they’re having a mental health problem is very difficult and now we’re putting up a barrier for kids.

“If we put up this barrier, I’m afraid we’ll see an increase in the suicide rate of kids because they don’t know where to go for help.”

Child advocates and the Colorado Bar Association have also expressed concerns about the bill.

“I think this bill really undermines people of this community being able to act in children’s best interests,” said Marie Avery-Moses with the Colorado Bar Association, who worries about the proposal impacting divorce and child protective cases.

S.B. 77 is scheduled to be heard Thursday by the Senate Education Committee, which meets at 1:30 p.m.