On Wednesday, America's highest court will consider whether a New Hampshire state law which restricts teenagers' access to abortion is constitutional.
Curbs will do for the moment - but an end to Roe v Wade is the goal of the anti-abortion movement
If it votes to reinstate the law, the case will mark a fresh limitation on Roe v Wade, the landmark Supreme Court ruling which established a woman's right to terminate her pregnancy.
But in some states - notably Mississippi - local laws have already rendered the 1973 ruling all but irrelevant.
The southern state of three million has just one abortion clinic - compared with 400 in California. While some hospitals do offer the procedure in extremely limited circumstances, the majority of women wanting an abortion leave the state to get one.
For the US anti-abortion movement, Mississippi is an excellent example of how to achieve the aim of curbing terminations without waiting - potentially in vain - for the Supreme Court to overturn the historic ruling which made them legal.
A succession of state laws in Mississippi have had a two-pronged effect.
They have made it harder for clinics to operate, but also harder for women - both practically and psychologically - to have an abortion.
If she is under 18, she must have the permission of both her parents to undergo the procedure. In the event of her being impregnated by her father, only her mother must consent.
Abortions may not be carried out in publicly-funded facilities.
After the woman has found hundreds of dollars to pay for the procedure, she is obliged to attend a counselling session, during which she is required by law to be told of a link between abortion and breast cancer. The federal National Cancer Institute reported in 2003 that there is no scientific evidence of a connection.
She is informed of all the services and agencies which could help her have the child. She must then wait for 24 hours.
Pro-choice groups argue this provision is particularly tough on poor women, who must thus take two days - often unpaid - off work. Anti-abortion groups say it gives her time to really think her decision through, armed with the facts.
This month, Mississippi was the subject of a PBS documentary - The Last Abortion Clinic. But while it is seen as having the most stringent collection of laws governing abortion, other states - such as Texas and Louisiana - have many similar restrictions.
In the past decade, state legislatures have passed more than 400 laws limiting access. The Alan Guttmacher Institute, a pro-choice think tank whose findings are quoted by both sides, says abortion is only available in 13% of US counties.
His mum says he's anti-abortion, but no-one really knows how Mr Alito would rule
Americans United For Life sees change at the state level as the most pragmatic way of proceeding.
Its president, Peter Samuelson, does not believe Americans are ready for an end to Roe v Wade - "not yet anyway", and does not in any case believe the ruling will be imminently overturned by the Supreme Court.
"But I think the court will uphold incremental changes happening at the state level. That's my prediction," he says.
"With each new state law public opinion moves with it. It's a slow process, but it's definitely now going in our direction."
US ABORTION RIGHTS
No state may ban abortion
But state may regulate all abortions
Curbs should not place "undue burden" on woman
But up to women to prove if restrictions damaging
Most common restrictions: parental consent, limitation on state funding, waiting periods
In comparison with the anti-abortion lobby, some observers feel pro-choice groups have lacked both a focused strategy and sufficient organisation in recent years - explained in part by the fact that a generation has grown up with no recollection of an era without Roe v Wade.
Certainly while every anti-abortion group contacted by the BBC provided spokespersons within hours of a request for an interview, at least two major pro-choice bodies - including America's largest, Naral, could offer no-one.
"Pro-lifers have been incredibly successful on the PR front," admits Dr Wendy Chavkin, chair of Physicians for Reproductive Choice and Health. "And we're seeing an increasing sympathy among Americans for the foetus."
At the same time, the pro-choice movement has struggled to find the right language.
Its perceived shift towards portraying abortion as a "necessary evil" which women often find traumatic but unavoidable has been seized on by the anti-abortion movement to bolster its case that, far from being liberating, terminations are a terrible experience for women and should be banned for their sake.
"We've got to work out a way of arguing our case which takes on board the fact that for some women it's very difficult, but for many others it is a positive and liberating decision," says Dr Chavkin.
"We shouldn't be so scared of stressing that."
Even if President Bush's conservative nomination for the Supreme Court, Samuel Alito, is accepted and does indeed prove hostile to Roe v Wade, he will not in himself tip the balance of the bench against the ruling.
Newly appointed chief justice John Roberts would have to decide similarly, and even then, a further vote would still be needed to reverse the decision.
A case would then have to be brought which fundamentally challenged the ruling. This is not a simple legal procedure.
In any case, even some of those who support abortion rights think an end to Roe v Wade might not be a bad thing after all.
Avowed pro-choice columnist Benjamin Wittes has argued that allowing such an issue to be decided by a group of judges "has been deeply unhealthy for abortion rights, for liberalism more generally, and ultimately for American democracy".
It would force the pro-choice lobby to argue their case with voters at the state level, so the thinking goes, and stop them relying on unelected courts to impose their views.
A number of states would thus become battlegrounds in a post-Roe future. Many would make abortion legal without a fight, and many others would allow the procedure with strict regulations attached.
Some - like Mississippi - would probably ban abortion outright.
And for many women with unwanted pregnancies in that southern state, little would change.