McCain in USAT (just posted):

In the end, Kagan’s interpretation of the Solomon Amendment was soundly rejected by the Supreme Court. By changing the policy she inherited and restricting military recruiter access when the prevailing law was to the contrary, Kagan stepped beyond public advocacy in opposition to a policy and into the realm of usurping the prerogative of the Congress and the president to make law and the courts to interpret it.
I have previously stated that I do not believe judges should stray beyond their constitutional role and act as if they have greater insight than representatives who are elected by the people. Given the choice to uphold a law that was unpopular with her peers and students or interpret the law to achieve her own political objectives, she chose the latter. I cannot support her nomination to the Supreme Court where, based on her prior actions, it appears unlikely that she would exercise judicial restraint.