PHILADELPHIA, July 27 (AP) -- The struggle over the Republican Party's position on abortion is shaping up as one-sided, a blow to GOP abortion-rights activists already disappointed in George W. Bush's choice of a running mate. The group of platform committee members chosen to take up the issue in pre-convention meetings Friday is led and dominated by anti-abortion Republicans, a hurdle in attempts by the other side to rewrite party principles. The panel is "overloaded with those who disagree with us," Susan Cullman, head of the Republican Pro-Choice Coalition, said Wednesday. "It will be very hard to get a majority." Bush has said all along he would not push for changes in the party's anti-abortion plank calling for a constitutional amendment to ban abortion, even though he believes abortion should remain legal in cases of rape, incest and to save the life of the pregnant woman. Hopes that he would choose a running mate who supports abortion rights--several had been considered--were dashed with the selection of Dick Cheney. The former Wyoming congressman built a strong anti-abortion voting record, although he has said more recently that the party should be open to differing views on the issue. The abortion-rights coalition called Cheney "reactionary" on issues important to women. "At this point, the only opportunity for our party to show respect for women is to abandon the platform language calling for a constitutional amendment to ban all abortion, without exception," Cullman said. "We're not calling for a pro-choice platform. We're asking for party principles that respect all our views." Platform committee members are expected to meet privately Thursday to receive a draft of the document. They will break into eight groups Friday, each dealing with different parts of the platform, and go over the language line by line, recommending changes. The full committee will sign off on the platform Saturday, two days before the national convention opens. The "family and community" subcommittee is led by two anti-abortion rights Republicans: Chris Georgacas, former state party chairman in Minnesota; and Ellen Sauerbrey, a two-time candidate for Maryland governor. Cullman said the panel, with about 15 members, has at least three abortion-rights members she knew of. Most of the rest are social conservatives, she said. Among them is Illinois Rep. Henry J. Hyde, who as 1996 platform committee chairman oversaw a process that turned divisive when party factions fought over an attempt to moderate abortion principles. The effort failed even though it had the support of the nominee, Bob Dole. Although the panel's makeup favors the party's social conservative base, contrary views on abortion at least are expected to get an airing. One of the members is Candace Straight of New Jersey, head of a political action committee that raises money for abortion-rights candidates for Congress. Abortion-rights activists have said they will try to bring the issue to the convention floor if the platform is left unchanged. The rules, however, make such a challenge difficult.