AUGUSTA — Democrats who support a bill vetoed Monday by Gov. Paul LePage said the governor misunderstood its intent and have vowed to try to override the veto.

LePage said in his veto message to the Legislature that LD 1044 would “create an unnecessary barrier for drug enforcement when drug use remains a significant scourge on our state.”

But Rep. Ann Dorney, D-Norridgewock, a doctor who sponsored the bill and who is affiliated with a clinic that distributes Suboxone, which helps opioid addicts break their habit, said her bill’s only purpose was to save lives.

“Too often the people around someone who has overdosed are afraid they’ll be arrested,” Dorney said. “Then when the EMTs arrive, the person is dead. The idea of this bill is to reduce deaths.”

The bill, which passed unanimously through the House and Senate, would create an affirmative defense against prosecution for drug possession for people who witness and report drug overdoses. That means if one person reports the overdose of another, he or she would have a statutory defense in court against a possession charge. It does not mean the person would be automatically immune from prosecution and conviction, Dorney said.

The original version of the bill would have made any evidence collected in that situation inadmissible in court, but Rep. Mark Dion, D-Portland, co-chairman of the Criminal Justice Committee and retired Cumberland County sheriff, said it was amended by the committee to avoid that.

“I think the governor kind of half gets it,” Dion said. “The original bill would have been exactly as the governor said in his veto letter. In the committee I think we struck a really good balance between public health concerns and public safety, and I wish the governor could have heard those discussions. I would say he might have changed his mind.”

In his veto letter, LePage called the intent of the bill “noble.”

“We want to encourage those overdosing on drugs to seek medical treatment,” he wrote. “However, those using illegal drugs or inappropriately using prescription drugs do not check the law books in those cases.”

LePage wrote that prosecutors already have the authority to drop possession charges if they deem them unjust.

Dorney and Dion conceded that point but said the intent of the bill was to provide defense attorneys and their would-be clients with a viable defense against a possession charge in cases where the defendant acts in the overdose victim’s best interest. They said the hope was that witnesses to an overdose would be more likely to call 911 and take other life-saving measures without fleeing the scene or wasting time cleaning up illicit material.