When Clinton ran for solid yardage in the middle decade the Redskins had a good offensive line. Chris Samuels was a regular pro bowl selection. When healthy, Jon Jansen was a solid RT. Randy Thomas was an athletic pulling guard who was close to pro bowl quality. When first acquired Casey Rabach had two quality seasons starting off his Redskins career at center.
Portis could have done worse. He could have had to run behind the line Stephen Jackson did in St. Louis. He could have run behind the line that Matt Forte did his first couple of years with the Bears.
Portis overall was a very effective back when healthy. He failed to stay healthy after his mid-20's because his offseason work habits never matched those of HOF quality performers that remained successful into their 30's. He came into camp out of shape and often took 3-4 games to 'hit stride'.
John Riggins admitted he hated lifting weights and refused to follow a regular offseason routine until he hit 28 and figured he was going to have to do more to stay in the NFL past 30.
The other thing with Clinton of course was the famous mouth that never stopped moving. He alienated coaches, teammates and almost everyone that followed the team with his ill-considered comments about his OL, position coaches and the media.
If you notice Mike Shanahan is doing the same things that Joe Gibbs did during his first stint, get rid of the controversial players who wanted to bleed in the newspapers and on the radio and thought of themselves to the exclusion of the team.
The draft picks this team makes from Kerrigan to RGIII seem to be hard-working players with a winning attitude. Even the one non-example, Trent Williams, who has showed his immaturity in getting suspended last year doesn't appear to be a guy that is going to get into trouble bad-mouthing teammates or coaches or being a locker room cancer.
Looking this roster up and down I can only point to one guy, DeAngelo Hall, that has the occasional slip of the tongue in the media which causes controversy. And he was already signed to a big money contract before Shanahan and Allen came on board.