Since the Patriots have had Wes Welker, apparently going to the Superbowl isn't good enough for some, many have said they aren't successful because they haven't won the big one in a while. A majority White team would have to win it all, and quickly and often so adding Whites would have probably have to be done gradually, the same way blacks have come to be the majority, it has been done gradually.
You would have to have everyone on the team buy into it, its more than just one coach, very large staff and have the remaining black players okay with it as well. I think many of these guys would feel racist for trying to win with a majority White team. They would have to approach things more like grabbing up underrated players for cheap. The undderated guys are usually White with a few exceptions. You could have found an impact player at every position in this draft if you looked hard enough and then UDFA, there were also plenty of talented guys up for grabs in free agency before the draft but then if you have a majority black team, you can't just replace them all with Whites in one year, which is why it would have to be gradual. The hardest positions to fill would be qb and offensive line, this is also true in college.
I think the closest we would get with most teams is a little over 50 percent without it becoming too noticeable. As far as the fans go look at some of the message boards about the draft, over half of the "omg wtf why did we get this guy" posts are about White athletes, Ebert, Matt Johnson, Shea McCllellin to a 4-3, Brandon Hardin, Jake Bequette etc. These were all productive guys too with measurables to back it up, the only one that should be questioned is Ebner but it was a late round pick, and if he were black it wouldn't be questioned, its a 215 pound guy with sub 4.5 speed.
Out of all the teams, The Patriots are built to do this. They have the qb, the linemen, Gronkowski, Welker, and now Ebert who could be the speed guy. Woodhead who can have at least a Warrick Dunn type role with Ryan Grant on short yardage stuff. On defense they have Mike Wright who can play 3-4 end or if they go 4-3 he can play DT next to sumo Wilfork and then Jake Bequette at DE, or OLB in a 3-4. They have a few White linebackers. They have Edelman who can fill the nickel corner role, they got Gregory who has been playing safety but is suited to play cornerback, if they felt they had 2 good corners already then FS, Ebner could fill in at one of the safety spots. This is not likely to happen of course, we will see a watered down version of this, White friendly for the NFL but not the best product to put on the field.