donald trump u.s. presidential campaign seal major staff reshuffle resignation friday campaign chairman republican nominee try end weeks upheaval focus beat democratic rival hillary clinton departure paul manafort come trump try week reset unorthodox bid white house fall behind clinton opinion poll nov. election trump say statement accept manafort resignation praise great work offer explanation departure trump aid say staff change usher great focus policy serious tone former reality tv host stick mission swap free-wheeling rally speeches prepare remark stick singular theme concentrate immigration trade deal law order speak dimondale michigan friday use teleprompter trump stay clear much hyperbole hallmark campaign attack clinton position trade agreements tell michigan crowd democrat would send auto job mexico nonetheless appear stray time prepare remark say black voters overwhelmingly tell pollsters prefer democratic candidates vote live poverty school good job 58 percent youth unemployed trump say hell lose trump never hold elect office refer staff change interview early friday son eric trump say unflattering headline manafort take toll think father want know distract know whatever things know paul deal tell fox news channel sunday morning futures also praise manafort work campaign question arise manafort previous work political party kremlin-backed former ukrainian leader viktor yanukovich federal investigators u.s. department justice examine american tie corruption ukraine cnn report friday investigation look work manafort firm another lobby firm podesta group head tony podesta whose brother john podesta chairman clinton presidential campaign clinton lead trump percentage point among likely voters accord reuters/ipsos opinion poll release friday aug. 14-18 online poll show clinton support 42 percent americans expect vote compare 34 percent trump 23 percent would side either candidate wednesday trump overhaul campaign team hire head conservative website breitbart news stephen bannon chief executive campaign move bolster combative image trump also promote adviser kellyanne conway data-driven political analyst campaign manager previous shake-up manafort first join team march take run campaign corey lewandowski fire campaign manager june clinton campaign point manafort ukraine work favorable comment trump make russian president vladimir putin sow question voters mind whether russian government unseen hand u.s. election russian officials reject accusation get rid manafort end odd bromance trump putin robby mook clinton campaign manager say statement john feehery republican strategist say would unsustainable manafort stay wednesday hire many cook kitchen say trump hire bannon see sign would hold back aggressive unorthodox campaign manner still trump offer rare word regret thursday time cause personal pain take-no-prisoners style friday also begin air first television advertisement since become republican candidate buy airtime crucial state ohio pennsylvania north carolina florida clinton already spend millions television advertise 30-second ad focus immigration say clinton would allow terrorists dangerous criminals country charge campaign dismiss karlyn bowman senior fellow american enterprise institute conservative think tank say trump still time turn around campaign note news shakeup come many americans enjoy summer vacation final stretch protract campaign traditionally start labor day fall sept. year sure public pay lot attention inside campaign stories say say trump clearly significant problems poll need something differently perhaps begin attempt clinton relief friday controversy use private email system secretary state u.s. federal judge rule clinton need give swear testimony lawsuit email issue trump campaign manager manafort quit trouble stretch