Evan Vucci, File, Associated Press
FILE - In this March 1, 2012 file photo, Republican presidential candidate, former House Speaker Newt Gingrich speaks in Atlanta. Gingrich is hoping that his decades of work building the Republican base in Georgia will pay dividends for him on Tuesday.

WASHINGTON — Newt Gingrich notched a home-field primary win in Georgia, and Mitt Romney moved ahead in Virginia and Vermont as Republican presidential rivals battled coast to coast in a 10-state Super Tuesday showdown.

More than 400 delegates were at stake on the busiest day by far of the race to pick an opponent to President Barack Obama in the fall.

Gingrich's victory was his first since he captured the South Carolina primary on Jan. 21, and he said it would propel him on yet another comeback in a race where he has faded badly over the past six weeks.