Republican presidential candidate Rick Perry's disastrous debate performance last week has hurt his campaign, but may not be fatal, a Reuters/Ipsos poll found. After watching a video of the Texas governor stumbling while trying to name three government agencies he would eliminate if elected, 48 percent of registered Republicans thought less favorably of him, the poll found. But while 31 percent of Republicans said Perry should drop out of the race, many more -- 52 percent -- said he should stay in. Perry's embarrassing memory lapse further roiled a Republican race already hit by the travails of Herman Cain, who...