"Be yourself and explain what motivates you," the president advised Clinton.
Cuban predicts a "Humbling at Hofstra" for Trump.
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Lee hasn't endorsed Trump and remarked earlier this year that Trump "scares me to death."
The campaign installed Tracey Winbush after her predecessor resigned over comments blaming Obama for racism.
The newspaper said Trump is "aligning himself with racists, strongmen and thugs."
Libertarian nominee Gary Johnson is at 10 percent in the survey.
The previous night, a man was fatally shot in the demonstrations.
Nearly half of Trump backers say he'll make a database to track Muslims.
Jonathan Easley 09/23/16 06:02 AM EDT
Election models show Clinton winning by everything from small margins to landslides.