I expect politicians to show passion while making speeches. I even allow the Pres to be a bit partisan when addressing the nation before a joint session of Congress. I do not expect it from the Justices of the Supreme Court or the Officers of the Joint Chiefs of Staff. Call me crazy.
Alito should not have betrayed his feelings by reacting publicly. The Supreme Court gets plenty of opportunities to communicate without having to encroach on the President's. Clearly, this was Obama's forum.