That's because he has an enormous protection ring. No, I'm not talking about the SS - I'm talking about academia, the mainstream media, and the rest of the democRAT thug machine that carry his tainted water day in and day out.
We saw how he reacted to a real citizen - you can bet that he'll never let anyone normal (like Joe the Plumber) get near him again.
If it ever comes down to that, it will come down to a contest of wills.
As long as the people targeted are under attack and the people doing the attacking don't suffer any serious losses on the field of battle and are safe from reprisal in their own homelands, then there is no cost to continuing to keep using overwhelming force to keep slapping the people around.
If that dynamic ever changes, then it will get to be a true contest of wills.