There is one really, really BIG difference - Donald J. Trump expects to get HIS agenda enacted, while Romney, Rubio or Jeb Bush would have presented an agenda which LOOKED similar, then traded it away for “comfortable” relations with the fakestream media and “comity” with the Democrat minority.
Don’t forget that Jeb! was the globalist one world order candidate, the candidate of the Davoisie - the compassionate conservative avoiding mass uprisings agains the ruling class by softening the harsh realities of global crony capitalism through socialist payouts to the lower classes at the expense of the upper middle class.