Mitt Romney and Newt Gingrich are enjoying their home state advantage in Massachusetts and Georgia respectively.
Newt Gingrich was the representative for Georgia's 6th district for 20 years, from 1979 to 1999, and he was overwhelmingly favored in the race. He was predicted as having a 75% of winning the state as early as February 28th. With 2% of the counties reporting, Gingrich has 46% of the vote with his nearest competitors, Romney and Santorum, with about 25% of the vote for each of them. This is almost exactly what was predicted by the most recent poll, which predicted that Gingrich would win 47% of the votes cast in Georgia.
The results out of Georgia are much better than any of Gingrich's recent efforts. In the primaries preceding Super Tuesday, Gingrich struggled to receive more than the 15% of the vote (getting 16% in Arizona). His long relationship with the state played a role, but he also put a lot of effort to make sure he carried it; he visited the state 8 times since the beginning of this year.
Mitt Romney also benefitted from home court advantage in Massachusetts, where he was governor from 2003-2007. In 2008, he won the state decisively against John McCain, receiving 51% of the vote to McCain's 40%. No counties have reported in the state, but the New York Times is already calling the race for Romney. Intrade also predicts a near-certain victory there for Romney.
Romney had a fairly popular term as Governor in Massachusetts, though he became less popular toward the end of his term. The more moderate and less socially conservative slant of Republicans in the state likely helped him as well.