Former Rep. Gabrielle Giffords lambasted the 46 senators who voted against an ill-fated bipartisan proposal to expand background checks on firearms sales and vowed to continue her fight for tougher gun laws. "Speaking is physically difficult for me," Giffords wrote in a New York Times opinion piece published online after the Senate rejected the compromise on Wednesday. "But my feelings are clear: I'm furious. I will not rest until we have righted the wrong these senators have done." Giffords, a Democrat, was seriously hurt in a 2011 shooting that killed six and wounded 13. She and her husband, Mark Kelly,...