(CNN) -- Albuquerque, New Mexico's largest city, will attempt something Tuesday that is believed to be a first on a city level: a municipal referendum to ban late-term abortions.
If the referendum passes, it is sure to be challenged in court. But it also may serve as a template for the next front on the anti-abortion battle.
Referenda that have put abortion on the ballot has been tried on the state level. But what Albuquerque will do Tuesday makes it unique among cities.
At the heart of the matter is a downtown clinic that is one of handful in the country that performs late-term abortions.
Over the summer, anti-abortion activists gathered thousands of signatures to force a special election that will ban abortions after 20 weeks -- and make no exception in the case of rape, incest. It does make an exception if the pregnant woman's life is at risk.
"We are really thinking strategically how to bypass the legislature," said Tara Shavers. "That's where our pro-life bills go and never make it out from committee. We call them 'kill committees.'"
Shavers and her husband run a ministry called "Project Defending Life" that was instrumental in gathering the signatures that prompted the referendum.
The wording of the ordinance says "unborn children" can feel pain after 20 weeks.
"This election has national implications," Shavers said. "We are in a blue state in a blue city. This is the ultimate test."
In early voting, which ended Friday, about 43,900 people cast ballots, according to the Albuquerque Journal. That's more than the 26,208 who voted in last month's mayoral election.
Both pro-choice and anti-abortion groups have plastered the airwaves and newspapers with ads, making their case.
Polls close at 7 p.m.