How Christian Conservatives Are Planning for the Next Battle, on I.V.F.

The pivot seems clear. The Republican Party of the post-Roe era is sidelining anti-abortion activists. Project 2025, the conservative blueprint with innovative abortion bans, has been disavowed by Donald Trump. And the new G.O.P. party platform even promises to advance access to in vitro fertilization.

But as Mr. Trump distances himself from the anti-abortion revolution his own administration ushered in, a powerful battalion of conservative Christians has pushed ahead. In recent months, they have quietly laid the groundwork for their fight to restrict not only access to abortion but also to I.V.F.

They are planting seeds for their ultimate goal of ending abortion from conception, both within the Republican Party and beyond it. They face a tough political battle since their positions are largely unpopular and do not reflect majority opinion, particularly on I.V.F.

As they see it, their challenge spans generations, not simply a single political cycle. And their approach — including controlling regulatory language, state party platforms and the definition of when life begins — reflects an incremental strategy similar to the one activists used for decades to eventually overturn Roe v. Wade.

“I expect there will be steps backwards as well as what we are working toward, which are long strikes forward,” said R. Albert Mohler Jr., president of the Southern Baptist Theological Seminary in Louisville, Ky., who has been newly mobilizing evangelicals against I.V.F.

The fall of Roe itself was far from linear, he noted. “It was nearly a half century of work, a half century of frustration, a half century of setbacks as well as advances,” Mr. Mohler said. “It will be a hard uphill climb, but that’s what we are called to.”