AUGUSTA — The state Senate rejected a bill Tuesday aimed at strengthening legal protections for religious freedom, which opponents say is unnecessary and could roll back decades of advances made for civil rights.

The Democrat-controlled Senate voted 19-16 in favor of rejecting Republican Sen. David Burns’ bill, which he said would ensure the state has a strong justification before it can infringe on someone’s religious liberty. The bill mirrors a federal law signed by President Bill Clinton in 1993, he said.

“This is not a partisan issue,” the Burns, a senator from Whiting, told lawmakers. “This is an American issue … it is the right thing to do.”

Opponents said the bill is unnecessary because religious freedom is already protected under the Maine Constitution and federal and state laws. Passing this bill would have significant unintended consequences, they said.

“I see this bill as a step backward … I see this bill as being used as a vehicle for a few extremists to hide behind the words of religious freedom as a way to circumvent our anti-discrimination laws,” Democratic Sen. Linda Valentino of Saco said.

Valentino questioned why the bill was being introduced now — after the approval of same-sex marriage in Maine and the Affordable Care Act, which requires health plans to provide coverage for certain types of contraceptive methods.

“It makes me wonder if this bill is really about religious freedom or is about trying to erode the existing women’s rights and gay rights that we fought so hard for,” she said.

Burns and others dismissed the idea that the bill allows the religious to get away with anything they want and say the opposition fails to understand the bill’s purpose.

“This is a vote that should unite us,” said Assistant Senate Republican Leader Roger Katz of Augusta, who supports the measure. “It’s a mystery to me that it does not.”

The bill now goes to the House for further consideration.