Secretariat was thought to not be a long track horse (didn’t have the endurance). Also, his NO was to start slow and come from behind. When he came on strong the thought was that he’d wear himself out by the home stretch.
But he didn’t run out of gas and, in fact, got stronger. And the rest is history.
I’m guessing you mean Trump is Secretariat, because Rubio isn’t.
Rubio is hobbled due to his Gang ctivities.