The New York Democrat's smooth road to confirmation was blocked by Sen. John Cornyn, R-Texas, who objected to including Clinton's name in a unanimous consent vote for several Cabinet nominees to be held Tuesday, The New York Times reported.
Instead, Senate Majority Leader Harry Reid, D-Nev., said he planned to hold a roll-call vote on Clinton's nomination Wednesday, which analysts said she was expected to win easily.
Cornyn said he made the move because he's not satisfied with measures taken by Clinton's husband, former President Bill Clinton, to address conflict-of-interest concerns regarding foreign contributions to his international foundation.
"This is not an effort to scuttle or block the nomination, but a legitimate policy difference," Cornyn spokesman Kevin McLaughlin told the Times. "Senator Cornyn's goal is to create transparency on all levels of government."
Hillary Clinton did not comment on the decision, but a spokesman for Reid told the newspaper, "She'll be confirmed tomorrow with an overwhelming bipartisan support."