It might happen, I don't discount the possibility, but this would be a seismic shift and a costly one for the Redskins, and I don't care who you are, old GM or new one, nobody wants to cost their boss all of the time, draft picks and money that have been invested in a former
#2 overall pick in his mid 20's unless they are absolutely certain his career will never amount to a hill of beans, and they better be pretty damn certain Mariota's will, because this is the kind of decision that gets people fired if it blows up in their faces, either way, with RG3 going on to have a good career elsewhere and/or Mariota not becoming what they think/hope he will be.
All that said, that might decide to do it anyway, but the right word here is might, not guarantee. There's way too much at stake here, way too many considerations, for Clayton to guarantee anything about this pick. He can have an opinion about what the Redskins might do, but as I said at the outset, I don't think guarantee means what John Clayton thinks it means.
Thats the problem with ESPN, too much acting like they have all the answers when they don't even know the questions.