An abortion opposition group says the upcoming presidential election is a critical one, as it kicks off a 40-day vigil Wednesday.

In Wisconsin, volunteers for 40 Days for Life will gather outside hospitals, as well as medical and family planning clinics in eight cities.

The number of campaign locations is on the rise and Wisconsin organizers say they're attracting more volunteers.

40 Days for Life cannot endorse political candidates. But where a politician stands on abortion can be a deal breaker for its volunteers.

Milwaukee coordinator Dan Miller says the upcoming election is crucial to abortion opponents, "I don't know what the next president will do with abortion. Our prayer is that it goes away; that Roe v. Wade is overturned."

Elizabeth Garibaldi is the local coordinator for 40 Days for Life in La Crosse. She says abortion, along with stem cell research and euthanasia, are the top issues for her as a voter, "Whoever becomes the president this year potentially could replace up to three Supreme Court judges and could make it 30,40 more years of a pro-choice court as opposed to putting three more pro-life judges on there."

Abortion rights supporters' are launching a national campaign in the upcoming weeks. NARAL Pro-Choice is targeting so-called "Obama defectors" in specific counties, including Milwaukee, Kenosha, and Racine.