washington/grand junction colo. u.s. president barack obama lacerate donald trump tuesday repeat assertions nov. election rig tell republican presidential candidate stop whine go try make case get vote opinion poll show fall back white house rival democrat hillary clinton trump intensify allegations although numerous study show voter fraud u.s. elections rare campaign rally grand junction colorado trump continue attack say press create rig system poison mind voters also use speech detail new initiative elect president constitutional amendment impose term limit members congress six years members house representatives 12 years members senate obama ask trump voter fraud assertions tuesday joint news conference white house rise garden follow meet italian prime minister matteo renzi respond blister attack republican candidate note u.s. elections run monitor local officials may well appoint republican governors state say case significant voter fraud find american elections obama say serious person would suggest possible rig american elections add invite mr. trump stop whine go try make case get vote trump speak grand junction rally tuesday even say obama stop campaign crook hillary get work job work border trump raise possibility weeks illegal activities could tarnish november election result cite scant questionable evidence include possibility vote cast dead people urge supporters show poll locations election day sharpen allegations even republican lawyers call assertions unfounded report title truth voter fraud brennan center justice new york university school law cite voter fraud incident rat 0.00004 percent 0.0009 percent august study washington post find 31 credible case impersonation fraud billion vote cast elections 2000 2014. arizona state university study 2012 2016 find similarly low rat point remark part civics lesson obama say trump win nov. would expectation hillary clinton offer gracious concession speech would job ... escort capitol would peaceful transfer power swear trump vice presidential run mate mike pence take soft tone trump campaign appearance north carolina say confident integrity election ensure pence add recent years instance prove instance voter fraud number republican-led state cite need prevent voter fraud pass laws strict identification requirements several strike court rule design hind minority vote trump trail clinton point national opinion poll accord average poll compile realclear politics last weeks trump never previously run office embroil one controversy another eclipse policy issue tax trade economy national security normally dominate final push presidential campaign three weeks leave election day early vote mail person already way many state trump grapple fallout release early month 2005 videotape hear brag grope women make unwanted sexual advance say remark locker room talk strongly deny allegations string women come forward since video emerge say trump grope touch inappropriately denounce accusers liars fame-seekers controversies backdrop third final three presidential debate hold wednesday even las vegas trump widely view defensive first debate appear improve performance second debate accord poll voters saw clinton victor wednesday debate like first one traditional format moderator pose question topics choose moderator chris wallace include debt entitlements immigration economy supreme court foreign hot spot fitness president tuesday press conference obama also criticize trump continue flattery russian president vladimir putin say step country trump praise putin strong leader monday suggest win next month might meet russian leader even swear president obama tell trump 'stop whine rig election claim