Pennsylvania Lt. Gov. John Fetterman is running for US Senate, but his floundering performance on the campaign trail has left many questioning whether he is fit to run for office — or even serve in the upper chamber of the house. [cut] Democrats who attended that speech said they are becoming uneasy about Fetterman. “Some tricky, cute tweet coming at the people of Pennsylvania again and again and again, with scarcely a word on substantive issues — if that is all his brain can remember, that is unacceptable,” one Democrat told me. “He seems to think he can ride out...