charlotte n.c. months sideline president barack obama join democratic presidential candidate hillary clinton campaign trail rally north carolina tuesday tell voters ready pass baton former secretary state obama take microphone charlotte chant hillary tell crowd never candidate prepare president clinton rival 2008 democratic nomination run last campaign proud things do together ready pass baton obama say likely first many trip year clinton behalf know hillary clinton go take know run race say obama return favor clinton back 2008 general election year wait battle u.s. senator bernie sanders democratic nomination endorse clinton last month become party presumptive nominee charlotte clinton precede obama say go build vision america president obama always champion vision future great things together north carolina trip come day federal bureau investigation director jam comey say agency would recommend clinton face criminal charge use personal email system secretary state white house spokesman josh earnest say obama get advance notice comey announcement say president would discuss fbi investigation clinton clinton campaign welcome end probe cast cloud campaign republicans seize comey criticism term clinton extremely careless handle email presumptive republican nominee donald trump due campaign raleigh north carolina tuesday criticize fbi recommendation tweet usual bad judgment first joint campaign appearance obama clinton initially plan soon clinch democratic nomination postpone follow mass shoot june 12 nightclub orlando florida tuesday obama appear ease back campaign trail mock trump promise make america great say america really great seek contrast clinton preparedness white house passion help work families trump political neophyte refer time guy everybody tweet nobody actually know take job sit behind desk say apparent reference wealthy new york businessman fondness twitter clinton hop reclaim north carolina democrats nov. election obama state 2008 general election lose narrowly 2012 re-election obama appearance former first lady close circle relationship begin cordially two u.s. senate colleagues grow tense presidential rival 2008 become close clinton serve obama cabinet first term clinton family play role obama elections clinton obama appear together unity new hampshire follow divisive primary fight 2008 clinton husband former president bill clinton give well-received speech 2012 democratic convention obama focus tout clinton strength character hop shore support among voters find untrustworthy weakness trump seek exploit clinton need obama woo young left-leaning voters back sanders make part president vote coalition 2008 2012. clinton also campaign high-profile liberal u.s. senator elizabeth warren appear late week vice president joe biden clinton obama travel north carolina presidential plane air force one trump characterize burden taxpayers clinton spokesman say campaign would cover portion travel cost obama hit campaign trail say ready 'pass baton clinton