In the heated debate over funding for abortion, one argument often silences both sides: Taxpayers aren’t paying for abortions anyway, since federal funding has been prohibited by the Hyde Amendment for four decades.

But Massachusetts is one of 17 states where abortions are taxpayer-funded — with money from the state.

Antiabortion activists are now trying to change that, launching a petition drive to change the state Constitution, which — the state’s high court ruled in 1981 — grants women on Medicaid the right to a state-funded abortion.