Georgia Democrats have not had much to smile about in recent election cycles. Republicans have tended to dominate legislative races, and they also have a tight grip on all statewide offices. But as the special election returns poured in last week, Democrats were grinning from ear to ear. They were able to win three seats in the legislature that for years had been held by Republicans. In the days before the election, hardly any of the political experts predicted that those seats would be flipped. Most of them never saw this coming.