The National Right to Life Committee has named its top legislative priority for 2012: passing a bill sponsored by an Arizona Republican that would ban abortions after 20 weeks in Washington, D.C.

With a Democratic Senate and President Barack Obama in the White House, the measure has virtually no chance of becoming law this year. But opponents are gearing up for a fight anyway, and they’ll be coming at the legislation from two different angles — as abortion rights supporters and as backers of more autonomy for the District.

Introduced by Rep. Trent Franks, the measure is modeled after legislation enacted in Nebraska, Kansas, Idaho, Oklahoma and Alabama. The bill would bar abortions from taking place after the 20th week of pregnancy — the point at which some medical experts suggest fetuses can begin to feel pain — unless there’s a clear determination that the mother’s life is in danger.

Because Congress has legislative powers over the District, Franks and others see an opportunity for the federal government to act on a less-than-national scale on the issue.

“I like to see children of all ages everywhere protected, but in this case, this offers us an opportunity to come together to at least to protect the children in the District, for whom we have absolute constitutional, exclusive right to legislate,” Franks told Roll Call.

That’s precisely the problem, argue opponents of the legislation.

“This is the first time that a bill that goes out to the District of Columbia is clearly and unmistakably aimed at women across the country,” Del. Eleanor Holmes Norton (D-D.C.) said. “The sponsors seek a federal precedent to run with … but if you want the easy way out, you could always try the District of Columbia, and it’s the most unprincipled way to approach an issue like this.”

Abortion rights supporters criticize the bill on policy, arguing it would bar the procedure in cases where the fetus faced serious health risks.

They are also enlisting supporters of D.C. autonomy, a group that has considerable overlap with backers of abortion rights.

“The basic thing here is that we’re always jumping all over the District as if it were our plaything,” said Rep. Louise Slaughter (D-N.Y.), co-chairwoman of the Congressional Pro-Choice Caucus. “We tell people to pay their taxes but that they can’t use their own money. … I’ve found that as long as I’ve been here to be very offensive.”

The women of the Congressional Black Caucus recently sent a letter to Democratic women in the Senate asking them to rally against the bill, which they called  “the newest threat to the rights of women in the District of Columbia.”

“I think those who support reproductive rights for women in D.C. also support D.C. home rule,” said Rep. Barbara Lee (D-Calif.), who orchestrated the CBC’s efforts here and said a meeting with their Senate supporters was in the works. “This is also a war against women, and it really seems to target low-income women and women of color in D.C.”

DC Vote, a leading organization backing District autonomy, is also calling on partners of its movement to oppose the legislation. NARAL Pro-Choice America said it is “already working with our national and D.C.-based coalition partners to prepare our allies in Congress to fight against a harmful abortion ban.”

Anti-abortion lawmakers see the issue differently.

“It’s too bad they even bring this issue of autonomy up because if you look at the Constitution — and I’m the chairman of the [House Judiciary] Constitution Subcommittee, so this isn’t something I take lightly — you see there is no possible rational argument that Congress doesn’t have the full right to legislate in the District of Columbia,” Franks said. “Even a liberal lawyer is going to have a hard time twisting that.”

National Right to Life Committee Legislative Director Douglas Johnson said that, above all else, the capital city should uphold a moral standard.

“The nation’s capital belongs to all the American people, and we don’t think most Americans believe their capital ought to be the capital of late-term abortions,” Johnson said.

The House Judiciary and Oversight and Government Reform committees would share jurisdiction over the bill. Neither committee’s staff had a sense of whether or when the measure might be considered, though Franks said he hopes his subcommittee will take it up “within the next couple of months.”

Oversight and Government Reform Chairman Darrell Issa (R-Calif.) has won some positive reviews from District officials recently for supporting increased budget autonomy for D.C., but he also opposes abortion and is a co-sponsor of Franks’ bill.

“The purpose of Rep. Issa’s efforts to grant the District greater control over its own budget isn’t to eliminate Congress’ constitutional authority over the District,” Issa spokesman Frederick Hill said.