The truth: Dem early voting rate is generally 6% below Republican rates (NYT's Nate Silver via PoliPundit).
Furthermore, in most areas that have high Dem concentrations, the early Dem vote does not match that proportionally, while the Republican early vote rates are significantly above their proportion for the same area.
Nevada does not look that great. Republicans and Democrats are voting in very close proportion, the GOP advantage is only 2%. May not be enough for Angle to win.