The antiabortion Susan B. Anthony List is targeting a very different kind of voter this cycle: For the first time, the lobby and advocacy group is pitching women in Democratic households.

The experiment is being tried in the tight Iowa Senate race between Republican state Sen. Joni Ernst and Democratic U.S. Rep. Bruce Braley.

That approach sounds counterintuitive, but 29 percent of Democrats identify themselves as “pro-life” on surveys. And while Democratic women have been blanketed with “war on women” messages, they’ve been mostly ignored by those on the other side of the abortion issue.

Over the past year, the SBA List has been trying the more scientific message-testing methods that Democrats have been using for years, looking less at what voters say about why they vote as they do — few of us really know what flips our electoral switches, it turns out — and more at what messages actually do move them.

Work done by Adam Schaeffer, of the conservative data-based consulting firm Evolving Strategies, found that in last year’s Virginia governor’s race, 10 percent more Democratic women who received just one robo-call changed sides, according to SBA List consultant Frank Cannon. The call the women received said that Democrat Terry McAuliffe opposed any limits on abortion. And 10 percent of the Democratic women who received that message either switched their vote or stayed home, as compared with those in a control group who did not receive a call.

In a second test, a randomly selected group of persuadable Florida women in Democratic households were told that Democratic congressional candidate Alex Sink opposed any limits on abortion after 20 weeks. Again, 10 percent more women in Democratic households who got that message told follow-up interviewers that they either had switched to vote Republican or had skipped the contest.

Obviously, peeling off 10 percent of those voters could decide a close race. So the SBA List is hoping the Iowa test is one it can pitch to donors ahead of the 2016 general election.

The SBA List has also hired 300 canvassers who make $10 an hour and have so far knocked on some 300,000 doors in Arkansas, Louisiana, North Carolina and Kansas. The group hopes the abortion issue will work in conservative candidates’ favor in Senate races in those states.

Although the group’s $3.5 million investment in these four states is modest in the current campaign environment, it is the first time that any group on the SBA List’s side of the abortion issue has been able to afford a real ground game.

The effort is possible because fundraising is up — the group has raised $11.4 million in this cycle, compared with $8.6 million at this point in the general election cycle of 2012, and $7.1 million in the more comparable midterms of 2010.

At the same time, though, the antiabortion movement has never been more bitterly divided, with a significant minority of advocates rejecting what they see as the national lobby’s morally unacceptable willingness to compromise — on rape exceptions and more.

Both the optimism and the split grew out of efforts to pass the Pain-Capable Unborn Child Protection Act. The act would outlaw abortions after 20 weeks of gestation, but in the eyes of antiabortion purists, it cedes the first 20 weeks.

Polling shows that while a strong majority of Americans say early-term abortions should be legal, support drops later in pregnancy. In 2012, a Gallup poll found that 61 percent of those surveyed said abortion should be legal during the first trimester, a figure that dropped to 27 percent for the second trimester and to 14 percent for the final three months. Public opinion on how far into pregnancy the procedure should be legal has fluctuated only slightly in the 18 years that Gallup has been measuring it.

“We can’t fail to take advantage” of all that that polling implies, says the SBA List’s longtime president, Marjorie Dannenfelser, who calls this “a breakout moment.”

Yet the national movement has also broken apart this year. Because the pain-capable bill passed by the House in 2013 includes exceptions for cases of rape, incest and risk to the life of the mother, some view it as a morally indefensible compromise by sellouts who have become, according to former National Right to Life Committee board member Daniel Becker, “more about saving politicians than babies.”

For Becker and a significant minority of other antiabortion dissidents, that the rape and incest exceptions were insisted on not by supporters of abortion rights but by the antiabortion lobby itself was a point of no return — the end of their partnership, and the beginning of a new coalition, the National Personhood Alliance. It held its founding conference in Georgia this month.

If you think the split is a polite difference of opinion among friends, think again: Erick Erickson, a conservative pundit and editor-in-chief of RedState.com, says that after he sided with the incrementalists, he was repeatedly called a “baby killer” on Twitter by fellow foes of abortion.

Rebecca Kiessling, a Michigan lawyer and personhood activist who was conceived during a rape, complains that some of her fellow conservatives have called her names, too, describing her as “an evil seed” who “must take after your rapist father.” She sees groups that support exceptions for rape as putting feminism above antiabortion principles.

But the break isn’t even. One of the pain-capable bill’s Senate sponsors, Lindsey O. Graham
(R-S.C.), pointed out in an interview that only a minority of those in the antiabortion movement favor a no-exceptions ban on abortions.

Polling backs that up, too: A CNN survey this year found that 20 percent of those polled said the procedure should never be legal, while almost twice that, 38 percent, said it should be legal in few circumstances. And “we should never, never touch birth control,’’ which an even smaller number of those who describe themselves as antiabortion oppose, Dannenfelser says.

While Dannenfelser’s group waits to see whether its experiment in Iowa will pay off, it already points to what it sees as one success — a NARAL Pro-Choice America ad against the SBA List itself. The commercial describes SBA List as being “as anti-woman as it gets,” and an image at the end of the ad seems to compare the organization to a sexual predator.

“We’re totally jazzed about it,’’ said the SBA List’s communications director, Mallory Quigley. “They see us as a threat.”