Various presidents before Clinton upheld an immigration ban on Muslims that existed since the events that led up to the first Barbary War. No president, regardless of party or policy, after the Barbary Wars could find a reasonable or justifiable reason to lift the ban. Even Lincoln who moved to free the slaves or Eisenhower who openly wanted to sign the Civil Rights Bill into Law, kept the ban going.
The one thing every president had in common regardless of policy differences was to keep that ban going. . .so why did Clinton do the one thing that no other president never dared!