Childrens’ advocates, elected officials and lawyers for the poor rallied on Wednesday to urge state Senate Republicans to raise the minimum age for criminal responsibility to 18 in New York — one of only two states that try many 16- and 17-year-olds as adults.

Wearing “RAISE THE AGE” pins at the steps of City Hall, the group cited scientific studies that have shown the brain isn’t fully developed until adulthood, a fact speakers at the rally said reduces culpability.

“This excessive regulation has led to horrific outcomes for the tens of thousands of youth who unfairly enter our criminal-justice system each year,” said the City Council Speaker, Melissa Mark-Viverito (D-Manhattan). “Instead of fostering recovery and providing access to resources that can lead to successful re-entry into society, this practice has only served to promote life-course criminality for our youth.”

Gov. Andrew M. Cuomo and Assembly Speaker Carl Heastie (D-Bronx) support the push, versions of which have failed in past.

Mark-Viverito and Legal Aid Society lawyers urged the public to call Republicans like Senate Majority Leader John Flanagan (R-Northport), who has previously opposed the hike.

Flanagan spokesman Rob Caroppoli did not return a message seeking comment Wednesday. Earlier in the week Flanagan told reporters in Albany that his Republican conference members are concerned about adequately funding the family court system, but, he said, “we can work those things out.”

Still reportedly to be decided: which crimes would be included in the change, the role of the family courts, and the source of the funding.

North Carolina is the other state that treats 16- and 17-year-olds as adults, though state legislators there have introduced a bill with bipartisan support to raise the age.

Early in American history, few municipalities distinguished between juvenile and adult criminality, but over the years, all the other states raised the age to 18. In the 1970s, light sentencing of high-profile criminals who committed heinous crimes prompted Albany to impose one of the country’s harshest juvenile systems.