As the debate over President Barack Obama's proposed gun legislation heats up on Capitol Hill, gun control advocates have a potential ace in the hole: Former Rep. Gabrielle Giffords, D-Ariz., the victim of a horrific incident of gun violence that interrupted a once-promising political career, is about to become eligible to lobby.

For Giffords, tomorrow marks the end of the official one-year "cooling off" period that former House members face when they leave office before they can lobby their former colleagues, according to Sunlight's post-employment lobbying tracker. Should she wish, she will be permitted to register as a ...