"He started whining before the game's even over," Obama said Tuesday during a news conference in the White House Rose Garden, adding that Trump's claim is "not based on facts."Obama also rapped Trump for his "flattery" of Russia's Vladimir Putin.
...."I have never seen in my lifetime or in modern political history any presidential candidate trying to discredit the elections and the election process before votes have even taken place. It's unprecedented," Obama said alongside Italian Prime Minister Matteo Renzi.
He cast Trump's warnings as a debunked myth, saying no evidence of widespread voter fraud exists.
"If whenever things are going badly for you and you lose, you start blaming somebody else, then you don't have what it takes to be in this job," Obama said.
"The degree to which he seems to model many of his policies and approaches to politics on Mr. Putin is unprecedented in American politics and is out of step" with bipartisan approaches toward Moscow, Obama said.