By Daniel Trotta (Reuters) – A Republican congressman who came out in support of gun control after a mass shooting in his area dropped out of the race for his re-election on Friday upon coming under withering criticism from Republicans who saw his policy shift as a betrayal. Chris Jacobs, a first-term U.S. representative from suburban Buffalo, New York, said he decided to withdraw to avoid “an incredibly divisive election” for the Republican Party. Jacobs embraced a federal ban on assault weapons and other gun control measures a week ago in the wake of two massacres. Authorities say a white gu…