Republican Sen. Scott Brown of Massachusetts says he'll vote against confirming Elena Kagan to be a Supreme Court justice.
The first-term senator was widely regarded as a potential Republican vote for President Barack Obama's nominee, who already has the backing of five other Republicans and is assured of confirmation by the Democratic-controlled Senate.
Brown announced his plans Thursday just hours before the Senate vote.
Brown says in a statement that he considers Kagan brilliant, but that he can't vote for a Supreme Court nominee who doesn't have judicial or courtroom experience.
Kagan has served as the Obama administration's solicitor general and has been dean of Harvard Law School.
© Copyright 2013 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.