former republican presidential candidate mitt romney openly critical donald trump republican party continue support bombastic billionaire president one former campaign operatives write stun op-ed roundly trash donald trump give rather glow endorsement democratic nominee hillary clinton man david nierenberg romney former finance chair piece appear cnbc website nierenberg say hillary clinton hillary clinton know stuff emotionally mature center respect enjoy work people backgrounds.she diplomatic skills need break gridlock washington lead country well america need steady hand tiller despite republican tie mitt romney date back 2006 nierenberg say party current standard-bearer trump dangerous major party presidential candidate lifetime maybe american history character temperament behavior definitely presidential.i think fit president speak positively foreign dictators act like one himself.this year however watch listen donald trump erratic daily bully rant brag scapegoating name-calling conscience three adult children let vote nierenberg also join call trump release tax return say decades candidates include successful business people release tax return trump think follow rule game defeat national priority exactly right time put party country long leave versus right republicans versus democrats one candidate intents purpose two-party political system qualify versus one dangerously unfit demagogue choice america put party country vote blue november.featured image via instagram fmr romney campaign chair break rank give full-throated endorsement clinton