washington u.s. president barack obama formally endorse hillary clinton white house bid thursday call democrats unite behind protract battle bernie sanders party nomination u.s. senator elizabeth warren massachusetts also back clinton thursday tell msnbc rachel maddow show presumptive republican presidential nominee donald trump genuine threat country clinton presumptive democratic nominee say mean world obama back bruise campaign nov. election clinton also say high regard warren fiery critic wall street really please good ideas support vice president joe biden also wad campaign thursday whoever next president god will view secretary clinton biden say speech american constitution society washington obama endorsement increase pressure sanders u.s. senator vermont bow race lend support clinton party focus defeat trump absolutely joy honor president obama years go fierce competitors true friends clinton tell reuters interview unexpectedly tough battle sanders challenge leave former first lady clinton make history reach number delegate need win party nomination week make first woman lead major u.s. party white house candidate obama enjoy rise approval rat near end eight years office appear clinton campaign trail next week wisconsin two opponents 2008 democratic presidential primary race obama bury rivalry serve secretary state four years clinton 2016 candidate white house believe best safeguard obama legacy think ever someone qualify hold office obama say clinton video fire wait get campaign hillary trump assail endorsement twitter want four years obama—but nobody else clinton campaign tweet brash response delete account sanders galvanize young voters call social equality measure rein wall street reluctant concede race despite concern among lead democrats continue party divisions could hamper clinton efforts beat trump obama senior democrats seek delicate balance rally party behind clinton alienate sanders supporters appear attempt gently ease sanders toward give campaign obama meet democratic socialist hour white house laugh warmly walk oval office although sanders tell reporters afterward still plan compete final nominate contest washington d.c. next tuesday say would work clinton defeat trump sanders welcome capitol hill senator harry reid top democrat senate reid say lawmaker vermont good place democratic colleagues suggest sanders close acknowledge defeat clinton hear single word try change fact nominee think accept reid tell reporters endorsement video obama recall party unity follow prolong primary battle clinton 2008 secretary clinton senator sanders may rival primary patriots love country share vision america believe obama say warren tell msnbc endorse clinton female fighter lead exactly country need warren populist credentials boost clinton ability court sanders voters prepare battle trump warren female democratic u.s. senator endorse clinton primary race clinton tell reuters warren similar view issue economic policy protect 2010 dodd-frank financial reform law consumer financial protection bureau warren push start trump say interview reuters last month would try dismantle dodd-frank law interview reuters clinton say overall economic package include plan rein wall street cut tax middle class would come first 100 days presidency defeat trump clinton previously say plan generate job invest transportation infrastructure spend immigration reform would among early priorities one things president obama say yesterday think job remind american people really serious job tough choices hard decisions high stake choose president commander chief clinton say know important get really good start white house say trump wealthy real estate developer become party presumptive nominee last month see large group rival well behind clinton campaign term fundraise policy infrastructure thursday top donors hold first official meet new york trump also meet industry leaders new york event organize oil billionaire harold hamm obama 'fired clinton democrats seek unify party