So they want someone who will bend to their ways in spite of the Constitution.
Leahy wants Alito to say Congress trumps all in laws.
Liberals believe the Constitution is outdated and should evolve based on their agenda. They believe gun rights, private property rights, etc. belong to a different era in our history and don't apply to today's Liberal ideology which reflects a international view or global approval.
They believe the U.S. should be held accountable to a world court including our soldiers they would allow to be tried by our enemies.