Washington, DC (LifeNews.com) -- Pro-abortion Sen. Hillary Clinton, a possible 2008 presidential candidate has donated $10,000 to the campaign of pro-life Pennsylvania Senate candidate Bob Casey. The donation may come as a surprise to some, but there may be self-serving reasons for the questionable donation.

Clinton is a darling of abortion advocates, who would likely strongly support her presidential bid should she decide to run. That's what has some observers scratching their heads about the donation to Casey's campaign.

According to the New York Post, Clinton made the maximum donation allowed by law to Casey from her political action committee, HillPAC. The donation was also the largest she gave to any candidate in 2005.

The gift is a departure from the view pro-abrotion groups hold about Casey's candidacy.

The National Organization for Women and Emily's List staunchly oppose Casey's bid, even though he is a Democrat, because of his pro-life views. The groups are sponsoring an online petition drive asking party leaders to sabotage his Senate bid.

According to the Post, their campaign blasts Casey as a "Republican-lite on women's issues" and bashed it as a "calculated effort by party leaders to build a so-called 'bigger tent' at the expense of women's rights."

But the reason for Clinton's donation may have nothing to do with abortion.

Casey is running against pro-life Republican Sen. Rick Santorum, a Clinton nemesis. Santorum drew Clinton's ire after he published a rebuttal book to her "It Takes a Village to Raise a Child." Santorum's was titled "It Takes a Family."

Meanwhile, HillPAC spokeswoman Ann Lewis, a noted abortion advocate, told the Post, "Sen. Clinton is committed to electing Democrats through contributions and campaigning on their behalf."

Should Casey defeat Santorum, which is a possibility given his 10 percentage point lead in the polls, it would aide Democratic efforts to recapture the Senate in the November elections.

For Clinton, supporting abortion is still a salient issue and she proved her credentials again with her recent vote against Supreme Court nominee Samuel Alito. Not only did she vote against Alito's nomination, she backed a filibuster engaged in by a handful of the most ardent pro-abortion members of the party.

About Alito, Clinton said "He will intensify his campaign to roll back" abortion rights granted in the Roe v. Wade decision.