Facing mounting pressure to strike down a near-total abortion ban revived last week by Arizona’s Supreme Court, Republican state legislators are considering efforts to undermine a planned ballot measure this fall that would enshrine abortion rights in the Arizona Constitution, according to a presentation obtained by The New York Times.

The 1864 law that is set to take effect in the coming weeks bans nearly all abortions and mandates prison sentences of two to five years for providing abortion care. The proposed ballot measure on abortion rights, known as the Arizona Abortion Access Act, would enshrine the right to an abortion before viability, or about 24 weeks. Supporters of the measure say they have already gathered enough signatures to put the question on the ballot ahead of a July 3 filing deadline.

Republicans in the Legislature are under tremendous pressure to overturn, or at least amend, the 1864 ban. Former President Donald J. Trump, the national standard-bearer of the Republican Party, directly intervened on Friday, calling on Republican legislators, in a frantically worded post online, to “act immediately” to change the law. A top Trump ally in Arizona who is running for the Senate, Kari Lake, has also called for the overturning of the 1864 law, which she had once praised.

Abortion rights have been a winning message for Democrats since the Supreme Court, with three justices appointed by Mr. Trump, overturned Roe v. Wade in 2022. And even though it is an objectively unpopular aspect of his White House legacy, Mr. Trump has repeatedly bragged that he is personally responsible for overturning Roe.

Republicans in Arizona, however, have already resisted efforts to repeal the 160-year-old law and are bracing for the potential for another floor battle on the ban that is looming for the Legislature, which is set to convene on Wednesday. The plans that circulated among Republican legislators suggest the caucus is considering other measures that would turn attention away from the 1864 law.

The presentation to Republican state legislators, written by Linley Wilson, the general counsel for the Republican majority in the Arizona State Legislature, proposed several ways in which the Republican-controlled Legislature could undermine the ballot measure, known as A.A.A., by placing competing constitutional amendments on the ballot that would limit the right to abortion even if the proposed ballot measure succeeded.

The plan, the document said, “Changes narrative — Republicans have a plan!” adding that the plan “puts Democrats in a defensive position to argue against partial birth abortions, discriminatory abortions, and other basic protections.”

One proposal would have the Legislature send to voters two other ballot initiatives that would “conflict with” and “pull votes from” the A.A.A. ballot measure. Ballot measures for a constitutional amendment can be proposed through a petition, as with the A.A.A. ballot measure, or through the State Legislature, and the document suggests that voters could read the Republican ballot measures first on the ballot if they are filed before the A.A.A. ballot measure.

One of the Republican ballot initiatives outlined in the presentation would enact an abortion ban after the fifth week of pregnancy, with exceptions for rape, incest and medical necessity. The other ballot option would propose a ban after the 14th week of pregnancy. The language of the measures would be intentionally written to mislead voters on when exactly an abortion would become illegal, according to the presentation.

The second option, for example, would be known as the “Fifteen Week Reproductive Care and Abortion Act.” But “in reality,” according to the presentation, “It’s a 14-week law disguised as a 15-week law because it would only allow abortion until the beginning of the 15th week.” Similarly, the wording of the five-week abortion ban would make abortion illegal “after the sixth week of pregnancy begins.”

An alternative to those two options would be to put forward a ballot measure that would take effect only if the A.A.A. ballot measure also passes. That plan, known as “conditional enactment,” would insert language in the state Constitution declaring that the right to an abortion in the A.A.A. ballot measure “is not absolute and shall not be interpreted to prevent the Legislature from” regulating abortion in the future. It would also include language used by anti-abortion activists, referring to “the preservation of prenatal life” and “mitigation of fetal pain.”

Ben Toma, the speaker of the Arizona House of Representatives, confirmed the authenticity of the document and said in a statement that it “presents ideas drafted for internal discussion and consideration within the caucus. I’ve publicly stated that we are looking at options to address this subject, and this is simply part of that.”

Dawn Penich, a spokeswoman for Arizona for Abortion Access, the liberal coalition organizing the A.A.A. ballot measure, said in a statement that the Republican presentation “shows yet again why Arizonans can’t leave our most basic and personal rights in the hands of politicians.”

Kate Zernike contributed reporting from New York.