Christie says Trump is biggest 'issue in this race'
While Christie has largely run in the primary as the biggest critic of Trump from within the GOP, polls show his message hasn't moved many voters.
Pressed on this on the debate stage, Christie sought to play down his low approval ratings from the party and suggested it was because he was telling the "truth" about Trump and Republicans, he said.
"He is unfit," he said of Trump, calling Trump a "dictator."
The former president -- his record, his rhetoric and his front-runner status in the race -- have to be discussed head-on, Christie said.
"There is no bigger issue in this race," he said.
-ABC News' Adam Carlson