hewlett packard enterprise co chief executive republican donor meg whitman reiterate opposition donald trump party presidential nominee compare fascist leaders adolf hitler benito mussolini accord media two source whitman make comment friday conference host previous republican nominee mitt romney challenge u.s. speaker house representatives paul ryan endorsement trump washington post report saturday two participants off-the-record session park city utah confirm whitman language reuters whitman could immediately reach comment billionaire former supporter fail candidate new jersey governor chris christie whitman actively work stop trump nomination include fundraise anti-trump super pac february technology ceo call trump unfit president since trump become presumptive republican nominee likely run democratic candidate hillary clinton nov. election ryan address 300 attendees session explain difficulty decision endorse post say include weather pressure house republicans lend back trump weeks hold ryan endorse new york businessman early june break number establishment republicans see trump rhetoric damage party opponents include romney republicans 2012 presidential nominee choose ryan run mate romney blast trump recent weeks attack make mexican-american judge preside case romney warn friday effect trickle-down racism could country presumptive nominee trump balance maintain outsider style help propel nomination court republican insiders could critical finance general election campaign well-funded clinton trump saturday show inclination make peace critics go twitter note romney choke like dog lose then-incumbent president barack obama 2012 reiterate campaign stop hp ceo whitman compare trump hitler mussolini