The chances are dwindling that a substantial number of Republicans will vote to confirm Supreme Court nominee Sonia Sotomayor, after a key GOP senator announced his opposition Monday morning.

Sen. Jeff Sessions, R-Ala., ended months of public indecision when he announced he would vote against confirmation, eliminating one of the last, best chances Sotomayor had of winning over prominent conservatives. Sessions, the top Republican on the Senate Judiciary Committee, had previously said he had concerns about her nomination but had stopped short of saying he would oppose her.