I've been around long enough to vividly recall WWII. Despite the revisionist claims, long after the events, internment was absolutely essential back then, and, for the same reasons, it's imperative now.
But more impractical.. Who you gonna inter? 4th generation christians of purely Arab decent? Turks? Blacks (lot of muslims, you know)? White Americans decended from original colonists that practice Islam? Anyone Islamic? Anyone not european? Of course, the most dangerous of all, White Christian Militia types!
So , what standards would you impose for internment and how would you keep them from expanding to any 'enemy of the state' as political fortunes change? Let the Genie out and it's all over for us as a somewhat free nation.