While the Democratic congressman representing the 12th Congressional District prepares for a November race to retain his seat, the four Republicans vying to oppose him are working hard to make their cases for area voters now. On Tuesday, voters throughout the region will choose among GOP candidates Rick Allen, Lee Anderson, Wright McLeod and Maria Sheffield to challenge U.S. Rep. John Barrow in this fall’s general election. The would-be opponents are spending the final days of their campaigns visiting with constituents and reaffirming the ideas they say make them the best choice to represent Georgia.