Otto Porter Jr. would be very good and I would not hesitate for a second to drop a max deal at him. He still has score for improvement in his own game, has improved in each of his 4 seasons in the NBA. He would be a perfect young veteran to get onto the team. Still young enough to grow with the team and be a core piece when/if the team starts being good again.
Having said that, there will be at least 2-3 other teams that would happily offer him the same contract and they might actually be more attractive to him as opposed to a laughing stock franchise that are professional sabotaging themselves. I this there is VERY little hope that even if Washington were not going to match the offers (which I think they will) that Porter would chose Kings over other 2-3 teams that would offer him the same amount of money.
One possible positive working for the Kings might be Garrett Temple. If Temple truly loves it here and believes that the franchise is on the right path (still to be determined) then he might be able to clarify a few things to Otto so that he is not making his decisions off perceptions. Still its a tough sell to leave a play off team to go to a rebuilding team when the money will be the same, possibly more and you are a Georgetown kid playing for Washington in the NBA.
I just can't see this being a realistic action to be honest. Odds are stacked well and truly against the Kings here.