Weeks before Obama's announcement, Jay Sekulow of the conservative American Center for Law and Justice launched a preemptive strike, warning his constituents that Sotomayor has a "very, very strict view of church-state separation." Advocacy groups on the left can only hope Sekulow is right. They worry that Sotomayor won't compensate for the loss of Justice David Souter, a reliable vote for a high wall of separation in case after case.
Souter and his fellow separationists didn't win often on the current Court, but they managed to score an occasional 5-4 victory.
Further thinning of their ranks would make it difficult, if not impossible, to muster five votes for a strict interpretation of the First Amendment's establishment clause.
Unless Sekulow has a secret document that will reveal all, Sotomayor's long judicial record on the U.S. District Court level and, since 1998, on the 2nd U.S. Circuit Court of Appeals tells us next to nothing about how she views the relationship between church and state. On the establishment clause, she is the great unknown.