With no Republican support, the best Ms. Stone-Manning can hope for is a tie vote in the committee, meaning that Senate Majority Leader Charles Schumer would need to call a vote of the full Senate to discharge her nomination. What’s more, the committee is headed by Sen. Joe Manchin of West Virginia, the Senate’s most centrist Democrat. He has not commented publicly on the nominee, and no committee vote is scheduled on her nomination. Ms. Stone-Manning told the committee in her questionnaire she had never been under federal investigation even though she received immunity from prosecution to testify in 1993 in the tree-spiking case.