President Bush is expected to sign into law this month a controversial new piece of legislation on abortion, which has just been approved by Congress.
It is the latest move in the bitter and deeply divisive debate about the provision of abortion services in the United States.
Anti-abortion groups are hailing the legislation as much-needed protection for hospitals and other health care providers who do not want to conduct abortions.
President Bush supports greater restrictions on abortion
But pro-choice groups describe it as a major new restriction on abortion and further evidence of a trend towards the erosion of abortion rights.
The Hyde-Weldon Abortion Non-Discrimination Act allows health care providers, including hospitals and insurance companies, to opt out of providing or paying for abortion services without the threat of penalty, such as having their access to public funds restricted or stopped.
It is a new version of similar legislation introduced back in 2002, which was then approved by the House of Representatives but not by the Senate.
And President Bush is thought to give the legislation his personal backing.
Groups who want access to abortion to be more restricted strongly support the legislation.
They see it as "conscience legislation" that allows health care providers to make their own choices about abortion services without facing the threat of being penalised by state or local authorities.
Douglas Johnson of the National Right to Life Committee accuses pro-choice groups of using state funding to exert pressure on health care providers to provide abortions.
"There has been in the United States an orchestrated campaign by pro-abortion pressure groups to force health care providers to participate in abortions," he told the BBC.
He cites as evidence a case in Alaska of a non-religious community hospital that was told by the courts it had to provide abortion services because it received state support.
He also gives examples of religiously affiliated hospitals that have had their attempts to enter into partnerships or even merger deals with other health care providers vetoed by state or local officials because the religious hospitals refuse to perform abortions.
Pro-choice advocates see the issue very differently.
David Seldin, the communications director of NARAL Pro-Choice America, says the new legislation will make it possible for anti-abortion groups to put pressure on health care providers not to provide abortion services and to refuse to discuss abortion as an option in counselling pregnant women.
"This is not about the individual conscience of one doctor," he told the BBC.
"It's about corporate responsibility. This [legislation] gives companies the licence to ignore state laws."
He says no law requires an individual doctor to perform an abortion against his or her will but at the moment health care providers do have a legal obligation, if they receive state funding, to provide abortion services, including counselling and referrals.
"This will allow corporations to impose their ideology on medical services," he said.
Supreme Court changes
The move comes as both sides of the debate are focussing on the Bush administration's second term and its implications for abortion services in the US.
At the heart of the discussion is the landmark 1973 Roe v Wade ruling that legalised abortion in the United States.
Opinion polls show that most Americans oppose Roe v Wade being overturned although pro-life groups argue that different surveys also show that the majority of Americans favour greater protection for the unborn child/foetus than Roe v Wade provides.
Pro-choice Republican Arlen Specter was criticised by conservatives
Both pro-choice and anti-abortion groups cite their own polls of public opinion as evidence to support their case.
Mr Johnson of the National Right to Life Committee says there is a trend towards supporting greater restrictions on abortion.
"We didn't get our current legal regime by majority vote, we got it from seven lawyers," he says.
"We think more and more Americans are figuring out how extreme Roe [v Wade] is."
Seven of the nine Supreme Court justices supported a women's right to abortion in the 1973 ruling, and his reference to the court highlights another key part of the US abortion debate.
Some commentators predict between two and four vacancies in the Supreme Court in the course of President Bush's four-year second term.
Pro-choice groups fear that President Bush will alter the composition of the court by favouring anti-abortion conservative candidates, and they believe the addition of more conservatives could lead to further restrictions on abortion rights.
"Roe v Wade is absolutely in danger," says David Seldin of NARAL Pro-Choice America. "We're very concerned about the direction the Bush administration's taking."
A recent row about comments on Roe v Wade by Senator Arlen Specter showed the strength of feeling.
Mr Specter is a pro-choice Republican who is a leading candidate for the chairmanship of the Senate Judiciary Committee, which plays a key role in appointments to the Supreme Court.
He was reported as saying that Supreme Court nominees who wanted to overturn Roe v Wade were unlikely to be approved by the Senate.
Right-wing groups responded with anger, describing Senator Specter as a "problem".
Some accused Senator Specter of softening his position in response by saying that, although he was himself pro-choice, he had in the past supported many anti-abortion nominees.
The composition of the Senate too has become more conservative since the election.
Mr Johnson says it is impossible to say whether Roe v Wade may be overturned in the next four years but he agrees the current Senate leans more to the right on abortion than its predecessor.
That could mean more legislative restrictions related to abortion, including laws requiring parental notification and restricting late-term abortions.