I think some of the Jewish vote has switched --- but I'm really not sure there have been the massive conversions of the Clinton-Gore voters to the other side. I personally have not met one --- and this hispanic area I'm in is mostly democrat. The Democrats figured the Green fringe didn't matter either --- but that cost them the election --- Nader votes made a difference.
Also I live in an area that very strong supported Silvestre Reyes for his stance on the border and his willingness not to back down to complaints by the Mexican government.
You do not need a massive shift. 5 to 10% in any group is enough for a landslide. That has happened and there is nothing the democrats are doing to rectify it. In fact, God love 'em, they are digging the hole deeper every day.