The Supreme Court appeared closely divided over affirmative action in college admissions on Wednesday as conservative justices expressed doubt about a policy at the University of Texas at Austin that used race as a factor in choosing applicants. Conservative Justice Anthony Kennedy, who often casts the deciding vote in close cases, raised the possibility of the case being sent back to a lower court for more evidence to be admitted. Some of the court's conservatives voiced skepticism about the success of affirmative action and its long-term value.