A convention to pick a new nominee will take place July 25.
The party faces uncharted waters since Platner withdrew from the race.
It's unlikely Iran attacks came from 'errant' group, Waltz said.
Graham "always led with faith, family, and South Carolina first," Scott said.
Graham died on Saturday after a "brief and sudden" illness, his office said.
This is a rush transcript of "This Week" airing Sunday, July 12.
