A national pro-abortion advocacy group has endorsed Illinois Senator Barack Obama over rival New York Senator Hillary Clinton in the race for the Democratic nomination for the presidency.

NARAL Pro-Choice America, an abortion “rights” organization, announced its political action committee’s endorsement on Wednesday, the Associated Press reports.  The group has supported Clinton throughout her career.

"Pro-choice Americans have been fortunate to have two strong pro-choice candidates in Senator Obama and Senator Clinton, both of whom have inspired millions of new voters to participate in this historic presidential race," NARAL president Nancy Keenan said in a statement. "Today, we are proud to put our organization's grass-roots and political support behind the pro-choice candidate whom we believe will secure the Democratic nomination and advance to the general election. That candidate is Senator Obama."

In addition to its support for legalized abortion, NARAL often opposes conscience protection laws for pharmacists and emergency room doctors who object to dispensing the so-called “Plan B” emergency contraception on the ground it could endanger a newly conceived child.

In a dispute over one such law in Wisconsin, Bishop of Madison Robert C. Morlino accused NARAL and its allies of being “more interested in promoting a state-supported, contraceptive ideology than they are in simply, reasonably, protecting women.”

Speaking to NBC Nightly News, Senator Clinton responded to NARAL’s endorsement of her opponent.

“I am disappointed because of the work that I've done for so many years,” she said.  “I'm proud to have the support of, you know, many other groups that — share my — views and my commitment to issues. But we're going forward.”

The endorsement has divided legalized abortion proponents.  Ellen Malcolm, president of the EMILY's List organization that promotes female pro-abortion candidates, criticized the endorsement. 

“I think it is tremendously disrespectful to Senator Clinton — who held up the nomination of an FDA commissioner in order to force approval of Plan B and who spoke so eloquently during the Supreme Court nomination about the importance of protecting Roe v. Wade — to not give her the courtesy to finish the final three weeks of the primary process," she said in a statement. "It certainly must be disconcerting for elected leaders who stand up for reproductive rights and expect the choice community will stand with them.”

Both Obama and Clinton hold similar positions on abortion. 

In a July 2007 speech to the Planned Parenthood Action Fund, Obama pledged that he would not yield to pro-life concerns.  When he held office in the state legislature, he opposed a state law that would have protected newborns who survived failed abortions.  The Illinois senator has also opposed any restrictions on the practice of partial-birth abortion

According to the Associated Press, officials with NARAL said its political committee board was about evenly divided between Obama and Clinton supporters.  The board eventually voted unanimously to support Senator Obama.

Officials said the decision was not meant as a snub of Clinton.  They said they backed Obama because he is overwhelmingly favored to win the nomination.   They believe he can heal what the group sees as a growing rift between black voters and white female activists the long Democratic nomination contest may have created.