After Robert Casey, the frontrunner for the Democratic nomination to challenge vulnerable Pennsylvania Senator Rick Santorum, joined Santorum in backing the Supreme Court nomination of conservative judicial activist Samuel Alito, Kate Michelman was not happy.

After saying she was “sorely disappointed by the lack of commitment to women and fundamental rights by the United State Senate,” the former president of NARAL Pro-Choice America ripped into Casey and local and national party leaders who back the socially-conservative Pennsylvania Democrat who is an ardent critic of the 1973 Roe v. Wade decision that guaranteed women the right to choose.

“As a Pennsylvanian, I am particularly appalled that local and national Democrats would hand our Senate nomination to someone who openly supports giving Roe an Alito-induced death,” said Michelman. “Those whose political successes have depended on the ballots and contributions of pro-choice voters but now facilitate the career of someone who would repeal those rights deserve special enmity.”

How angry was Michelman?

The veteran activist who has lived for almost three decades in Pennsylvania might just jump into the Senate race herself.

“After Casey announced his support for Alito, I got calls from around the country,” says Michelman in a Legal Times article on the fallout from the Alito fight. She tells Legal Times that she has been urged by Democratic donors and feminist groups to run this fall as a pro-choice independent challenger to anti-choice Republican Santorum and anti-choice Democrat Casey.

If she does, it will be a blow not just to Casey but to liberal college professor Chuck Pennacchio, who has had worked hard — in the face of opposition from most prominent Democrats in Pennsylvania and Washington — to mount a Democratic primary challenge to Casey.

The filing deadline to enter the May 16 Democratic primary passes on Tuesday. But the filing deadline to run as a third party or independent candidate remains open until August 1. Theoretically, Michelman could wait until Democrats make their choice and then run if Casey is nominated. In reality, however, the prospect of a Michelman run will divert energy — and potentially resources — from Pennacchio’s already uphill campaign.

Says Pennacchio, “A third party pro-choice candidacy would also divide Pennsylvania Democrats. Since 2000, Al Gore, Ed Rendell, John Kerry, and Arlen Specter have proven that Pennsylvania is a pro-choice state. The best way to defeat Rick Santorum in 2006 is for Democrats to nominate a pro-choice candidate who can and will unite Pennsylvania?s pro-choice majority and make a third party pro-choice candidacy unnecessary. My campaign has established county organizations around the state, and is already uniting Pennsylvanians by fighting for what they want: choice, universal health care, an end to the Iraq War, and other widely held majoritarian views.”

But, with expectations high that Casey will be the nominee, the argument for getting started now on an independent candidacy cannot be disregarded altogether. Nor can the prospect that, with sufficient funding and the right breaks, Michelman could be a serious contender.

The classic case of a three-way race for a Senate seat was seen in 1970 in New York State. Both the Republican incumbent, Charles Goodell, and the Democratic challenger, Richard Ottinger, were strong critics of the Vietnam War who embraced generally liberal positions on domestic matters. William F. Buckley’s brother, Jim, running on the Conservative Party line, backed the war and steered to the right on social issues. Buckley, whose campaign drew substantial financial support from conservatives around the country and support from many renegade Republicans at the state and national levels, did not win a majority of the vote. But with the major party candidates dividing up the liberal base — Goodell got 24 percent of the vote, Ottinger 37 percent and Buckley 39 percent — the outsider who wasn’t supposed to stand a chance won the seat.