Rep. Trent Franks had endorsed both Ted Cruz and Marco Rubio for president.
Cruz's comments come as investigation into Clinton's use of a private email server continues.
Trump is rallying supporters in St Louis, Mo.
The GOP front-runner said they should respond if protesters provoke violence.
"Vince McMahon should have put them on, because they were WWE."
The former neurosurgeon said Trump is the leader who can make change in Washington.
Trump said Carson called to offer his endorsement.
Trump's campaign event is taking place in Palm Beach, Fla.
But Rakeem Jones said the man charged with hitting him will "probably be bailed out."
Lee would be the first sitting senator to endorse Cruz.