Obama was an unknown quantity in 2008. He could be all things to all of his voters.
Warren has a record of missteps and silly things she said. It will come back to haunt her in a presidential race.
There was a time when I would have agreed with you, but not now. With the American voter being so uninformed and actually stupid anything is possible now. Add to that the fact that the more lefty a democrat, the better his/her chance of being their nominee.