Trump, reacting to comments Biden made about him earlier in the week at an anti-sexual assault rally, tweeted Thursday: "Crazy Joe Biden is trying to act like a tough guy. Actually, he is weak, both mentally and physically, and yet he threatens me, for the second time, with physical assault.
"There is institutional racism, it exists throughout our society," Biden said highlighting that efforts to curtail racism are not enough.
President Barack Obama said he could envision Republican presidential candidate Donald Trump giving a State of the Union address - but in a comedy skit
Vice President Joe Biden apologised on Wednesday for referring to people who squeeze US military personnel serving overseas on loans and other financial issues as "Shylocks," a reference to a stereotypical Jewish character in Shakespeare.