I thought the same thing myself for awhile....but now I think its just the fact that he thinks Bush is a loser and he will not stop punching him until Bush is out of the race.
As long as he whack Bush he is seen as strong by clobbering something.
Both are possible at the same time however.....haha
When thread is started by TBBT, one has to ignore content and enjoy thread for entertainment purpose.
Trump may see Jeb as weak.
Trump is a bully.
Bullies love to pick on people they perceive as weak.
It’s just kinda fun for them.
(another possible explanation)