It would be very unwise for Romney to call him a monster or seem to be doing so by agreeing.
That is the red meat the MSM is waiting for to go 24/7 with Romney not having a Presidential temperament...or worse, starting the racist drumbeat pounding. Romney doesn’t need to make any gaffs - as Obama has made huge gaffs in the past week alone. Anything by Romney that will get Obama’s own words our of the headlines and the commentaries is not helpful.
He doesn’t need to do that...because it is stupid to do it and it adds absolutely nothing of value.
He just should not have addressed it at all. Simply answered the question and ignored the monster comment.