Leaders of the anti-abortion movement believe they are closer than they have been in 50 years to achieving their goals, and local efforts like these are at the heart of their plan to get there. They see this political moment — a White House that advances anti-abortion priorities, a Supreme Court poised to tilt in a conservative direction, and a possible third Supreme Court seat to fill while Mr. Trump is still in office — as a rare opportunity, and one they have worked for years to create.

Some say they feel excited; others are cautiously optimistic. They are all definitely determined.

“Abortion is the single most significant human rights abuse of our time,” said Jeanne Mancini, president of the March for Life, which has brought tens of thousands of protesters to Washington every year since the Supreme Court legalized abortion in 1973. “I have a lot of hope for incremental laws — for example, a late-term abortion ban.”

While a majority of Americans have long believed abortion should be legal in most or all cases, the vocal anti-abortion movement is pursuing its goals at the local level. In states like Indiana, whose legislature has a Republican supermajority, activists have repeatedly pushed incremental laws that restrict abortion, require parental involvement or limit state funding.