The Libertarian nominee struggled in a live TV appearance to name a foreign leader he admires.
Trump said he's not worried about the Clintons bringing up his own past.
Reports surfaced that Trump violated the U.S. embargo.
Trump has offered both praise and criticism of the German leader.
“Those are fan polls, man,” Todd said.
Rafael Bernal 09/29/16 05:49 PM EDT
Clinton adds that she admires Germany's Angela Merkel.
"What a rigged deal, I tell you," Trump said in New Hampshire.
Christie denies he is under consideration for the new role.
Obama and Romney spoke at the annual dinner in 2012.