Mitt Romney's reemergence this election cycle as a harsh critic of Donald Trump has been crippling for his favorability among Republican voters, a new poll shows. Romney, the 2012 Republican presidential nominee, is seen as favorable by just 28 percent of Republican primary voters, according to a Public Policy Polling survey released Tuesday. A startling 62 percent of Republican primary voters view him unfavorably, the poll found, and 10 percent said they were not sure. That net favorability of minus-34 percentage points is a dramatic drop from polling conducted prior to 2016. In January 2015, for example, Romney was seen...