Army 1st Lt. Shaye Haver, center, and Capt. Kristen Griest, right, pose with other female West Point alumni last year at Fort Benning, Ga. Haver and Griest are the first female graduates of the Army's rigorous Ranger School. (John Bazemore/AP)

Worshiping here at the Shandon Baptist Church, just outside the Army’s Fort Jackson, Katie Smith has heard about the idea endorsed by some GOP presidential candidates to register women for the military draft.

She does not like it.

“As a Christian, I believe women are called to be with their families,” said Smith, 34. “If women are pushed even further in the military, I worry we’re going to see the family break down even more.”

The odds that 18-year-old women might someday be drafted into the military and forced to go through basic training here at Fort Jackson, the Army’s biggest training site for new recruits, are remote at best. So how did the issue become a subject of heated debate and division inside the Republican primary?

The answer starts with Sen. Ted Cruz (R-Tex.) and a policy change in the White House.

The Obama administration decided in early February to open up all combat jobs to women, prompting the question of whether women must register for the draft, as men do. Republican presidential candidates Jeb Bush and Sen. Marco Rubio (R-Fla.) said that they should, leading an incredulous Cruz to rail this week: “Have we lost our faculties? Is political correctness so consuming that we’re not willing to say that’s just nuts?”

For Cruz, who has cast himself as a true traditional conservative, the possibility that women might be forced to register for the draft offered a perfect opening to draw a contrast between himself and more establishment-friendly Republicans, such as Bush and Rubio.

The issuehas little to do with military effectiveness, but has deep roots in the nation’s culture wars going back to the 1970s and 1980s. Here at Shandon Baptist Church, the question of drafting women quickly pivots to broader topics such as the role of women in society and whether they should be treated the same as men.

Shandon is home to more than 7,000 worshipers, including a big contingent of soldiers from Fort Jackson. Each year, more than 36,000 male and female recruits endure 10 weeks of basic training here before moving on to other bases and units.

In the final days before the crucial South Carolina primary, Cruz in particular has used the issue to appeal to the conservative, evangelical voters who feel as though they have been on the losing end of the country’s culture wars for the past eight years. Cruz has often cast the issue in the harshest terms.

“As the father of two daughters, I can tell you, we are not going to draft American women into military combat,” Cruz said to cheers Tuesday in South Carolina. He promised to review the Marine Corps’ failed request to bar women from combat jobs, saying that he “would not simply bow down to political correctness.”

A week earlier, Cruz railed against the notion that the government would “forcibly conscript our daughters” and “put them in a foxhole fighting a jihadist, a 220-pound psychopath trying to kill them.”

His stand has drawn cheers from some conservatives who sense that Cruz has latched on to an important wedge issue. “A big deal,” Bill Kristol, editor of the Weekly Standard, tweeted about Cruz’s stand. “Cruz can distinguish himself from the rest of the field and steal some of Trump’s anti-P.C. thunder.”

Cruz’s attacks led Rubio to reconsider his stance, telling reporters last Friday that he doesn’t “support drafting women and forcing them into combat roles.” Rubio has also questioned whether the Selective Service system — which requires 18-year-old males to register for the draft — is even necessary anymore.

The question of drafting women arose only after Defense Secretary Ashton B. Carter ordered the military to open up all combat jobs to women, with no exceptions. This month, a few days after Carter’s order became official, the military’s top brass were called to testify before the Senate Armed Services Committee, where Sen. Claire McCaskill (D-Mo.) raised the draft issue. A 1981 Supreme Court decision found that women should not have to register because they were barred from serving in front-line combat positions.

Since the 9/11 attacks, women serving in military support jobs have engaged in fighting in Iraq and Afghanistan. They have received awards for valor under fire, and 161 have lost their lives. Now that the restriction on women filling combat jobs has been lifted, McCaskill asked, shouldn’t they be treated exactly as men?

The Army’s four-star chief of staff and the Marine Corps’ commandant both said they should, setting off a scramble on Capitol Hill, where Sen. Mike Lee (R-Utah) said he plans to introduce a bill that would prevent the Obama administration from forcing women to register for military service. “We simply can’t trust this president or the courts to honor the law and protect our daughters,” he said. Both Cruz and Rubio have pledged to co-sponsor the legislation.

In the House, two Republicans have taken a different approach. The Draft America’s Daughters Act, sponsored by Rep. Duncan D. Hunter (Calif.), a Marine veteran, and Rep. Ryan Zinke (Mont.), a former Navy SEAL, would require women to register for the draft. Hunter and Zinke — who oppose opening combat jobs to women and plan on voting against their own bill — said they hope the legislation will force a larger debate over the wisdom of the Obama administration’s policies on women in combat.

The question of forcing women to register for the draft has roots in conservative policy circles and the culture battles of the 1970s and 1980s. In an effort to block the Equal Rights Amendment in Congress, conservative icon Phyllis Schlafly argued that passage of the bill would compel the federal government to force women to register for the draft. At the time, memories of the disastrous Vietnam War were fresh, and no one was in favor of forcing women into military service.

Today, the roles have reversed and the strongest support for forcing women to register for the draft comes from feminists and military experts who pressed to open up combat jobs to women who can meet the physical requirements.

“This is a fundamental responsibility of citizenship,” said Nora Bensahel, a scholar in residence at American University’s School of International Service. Cruz’s objection to forcing women to register for the draft implies that they are “second-class citizens,” Bensahel said. “To exclude women from that fundamental citizenship is in­cred­ibly disturbing.”

It’s an argument that resonates with Kiersten Peterson, 18, who just graduated from basic training at Fort Jackson, having spent the past few days hiking and sleeping in the cold. Clad in green Army fatigues, her hair pulled back in a tight bun, Peterson shopped with her father just outside the base.

“If women want equal rights, we should be prepared to do everything the men do,” Peterson said. “We don’t get to pick and choose when we want equal rights and when we don’t.”

At Shandon Baptist Church this past Sunday — less than a week before the primary — the sentiment was almost universally against drafting women. The church’s pastor, Dick Lincoln, preached his second sermon of the day to a crowd of more than 1,200 in a sanctuary that was bathed in purple light and included two large video screens for those watching from the back. His congregation was largely conservative, and was following the state’s GOP primary closely.

The issue of women and the draft, he said, served as a proxy for other bigger questions, such as the meaning of equality during a time of shifting social mores, gay marriage and changes to the traditional American family.

“Does equality mean men and women are the same?” he asked. “It is a philosophical question, but it cuts down to the flesh and bone after a while.”

Katie Zezima in Mount Pleasant, S.C., contributed to this report.