washington brent scowcroft national security adviser two republican u.s. presidents wednesday endorse democrat hillary clinton president donald trump snub republican party likely nominee prominent member security wing presidency require judgment knowledge make tough call pressure republican elder statesman say statement believe hillary clinton wisdom experience lead country critical time scowcroft 91 serve national security adviser presidents gerald ford george h. w. bush ford president 1974 1977 bush 1989 1993. join number well-known republicans defect due prospect trump presidency include richard armitage deputy secretary state president george w. bush armitage give clinton 68 secretary state democratic president barack obama back last week trump appear republican appear want learn issue go vote mrs. clinton armitage tell politico time trump campaign immediately respond request comment scowcroft endorsement clinton trump 70 never hold elect office often boast campaign trail relative newness politics appeal voters disillusion current political climate despite facet appeal help trump beat 16 rival campaign primary phase become party presumptive nominee establishment republicans worry inexperience brash style alienate foreign ally international partner among proposals trump criticize nato cornerstone u.s. security policy say would consider let japan south korea develop nuclear weapons instead rely unite state protection north korea china secretary clinton share belief america must remain world indispensable leader scowcroft say understand leadership engagement beyond border make world therefore unite state secure prosperous trump say would strengthen national security offer detail plan proposals build wall u.s.-mexican border temporary ban muslims enter unite state many national security experts express alarm propose ban warn trump fiery rhetoric campaign trail fuel extremism former ford bush national security adviser scowcroft endorse clinton