Retired Lt. Gen. Michael Flynn later apologized.
Hillary Clinton and Tim Kaine will do a bus tour of Pennsylvania and Ohio.
A user said Trump's "insecurity is bottomless."
Jeff Weaver called for Debbie Wasserman Schultz to step down.
"Most of us stopped the name-calling about fifth grade."
Bernie Sanders still supports Hillary Clinton after an email leak showed that party leaders favored her.
Sanders said Sen. Tim Kaine (D-Va.) is more conservative than he is.
Trump gained 2 points across 11 battleground states.
"If I can do that as a service to our country, I'd love to do it."
"Bernie Sanders is the one who should be concerned," he said.