On the day Senate Judiciary Committee Democrats unanimously rejected the Supreme Court nomination of Judge Samuel Alito, their anointed candidate for what is seen as the country’s most vulnerable Republican-held Senate seat announced his support for the President’s pick. Pennsylvania State Treasurer Robert Casey Jr., the man Democrats and liberal interest groups have lined up behind in his challenge to right-wing Republican Senator Rick Santorum, dismissed concerns about Alito that had been raised by the very senators and organizations he expects to help elect him in November. According to Casey, “The arguments against Judge Alito do not rise to the level that would require a vote denying him a seat on the US Supreme Court.”

For activists like Kate Michelman, former president of NARAL Pro-Choice America, the move confirmed concerns about Casey. “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. But Casey has always been antichoice. What worried even some Democrats who’d made their peace with Casey’s abortion stance–on the basis of his behind-the-scenes assurances that he would not reflexively support antichoice nominees for the High Court–was the fact that Casey, supposedly a big backer of worker and consumer rights, so casually rejected serious arguments that had been raised about Alito’s pro-corporate bias.

It’s no secret that prominent Democrats–including Hillary Clinton, whose political action committee has donated $10,000 to the Casey campaign–are backing a candidate critics call “Santorum Lite” because they think Casey, whose father was governor and who’s been elected three times statewide, is known and seemingly popular. He consistently leads Santorum in the polls, and if his lead holds through November, Democrats will be one seat closer to retaking the Senate. But Casey’s lead has been dwindling as Santorum’s camp takes shots at him from the right while prochoice and pro-gay rights moderates and liberals grumble about the Democrat’s conservative stances on social issues.

The Casey controversy illustrates the perils of early intervention by Washington Democrats in the process of selecting Senate candidates at the state level; in their drive to find a strong contender, DC power brokers often bet on candidates who are more conservative than the grassroots activists who form the party’s base. It’s especially frustrating to Pennsylvania activists, who watched national Democrats elbow out of the contest Barbara Hafer, a popular prochoice woman who’d won a number of statewide races, to make way for Casey. “A lot of women feel ignored, like the boys decided that this is a throwaway issue,” Kathy Miller, outgoing president of the Pennsylvania chapter of the National Organization for Women, told the Philadelphia Daily News.

There is similar frustration in Tennessee, where another Senate candidate anointed by the Democratic Senatorial Campaign Committee, Congressman Harold Ford, came out against an anti-Alito filibuster on the day civil rights groups endorsed the last-ditch effort to block the nomination. Hilary Shelton, director of the NAACP’s Washington bureau, described the move by Ford, a member of the Congressional Black Caucus, as “deeply concerning to us.” Ford’s primary foe, State Senator Rosalind Kurita, hasn’t made a big issue of Ford’s stand. It’s a different story in Pennsylvania, where Chuck Pennacchio, a college professor and former Congressional aide, has positioned himself as the progressive alternative to Casey on issues ranging from abortion rights to the Iraq War. Along with another candidate who’s challenging Casey, attorney Alan Sandals, Pennacchio seized on Casey’s defection to the Alito camp. “Democrats will have a choice between a watered-down version of Rick Santorum and a strong Democrat who will consistently stand with them on the issues they care about,” argues Pennacchio. Recalling that his party lost when it ran a social conservative against Santorum in 2000, Pennacchio says: “An antichoice Democrat cannot beat an antichoice Republican in a high-profile race.”

Pennacchio may be right. When a contender like Casey splits with the base, it raises worries about whether that candidate offers enough of an alternative to generate the high turnout needed from liberal partisans, let alone to attract the votes of those prochoice independents and Republicans whose defections could tip Pennsylvania and the Senate to the Democrats. A late-January Op-Ed News.com-Zogby People’s Poll actually showed that when voters are informed about Pennacchio and his positions, he beats Santorum by a slightly wider margin than would Casey. Unfortunately for Pennacchio, he’s still struggling to get his message out. He trails far behind Casey in the primary polls and won’t be getting any help from DC Democrats. But his grassroots campaign will be raising alarm bells between now and the May 16 primary, warning Democrats who care to listen that they run the risk of nominating a candidate who can’t win in November.