Q: Does Hawaii have a missile defense system?
A: Yes. A Terminal High Altitude Area Defense (THHAD) unit is stationed on the island of Kauai. The unit successfully intercepted two short-range ballistic missile targets almost simultaneously. Here's a video of that unit in action:
THAAD is the only missile defense system that is capable of intercepting missiles both inside the atmosphere and outside the atmosphere. Other missile systems intercepts one or the other.