Trump defends 'spirited' campaign chief

Donald Trump defended Sunday his campaign manager, who appeared to grab a protester at a rally for the Republican presidential frontrunner that was again marred by demonstrations and sporadic violence.

It is just the latest controversial turn in the real-estate mogul's unconventional run for the White House, but it appears to have done little harm so far to his presidential ambitions and he is in pole position for the Republican nomination for November's election.

On Saturday afternoon anti-Trump protesters blocked a road near Phoenix and in the evening there was more unrest at a Trump rally in Tucson. Among the incidents, cameras caught a member of the crowd repeatedly kicking and punching a protester and video also showed Trump's campaign manager Corey Lewandowski caught up in a melee.

Lewandowski appeared to grab one man by the scruff of the neck, with a member of Trump's security detail also involved in the fracas.

"No, he didn't touch him, that was someone else pulling him (the man) back," Trump, a reality television star who has never held elected office, told the ABC News program "This Week."

"I give him credit for having spirit. He wanted them to take down those horrible profanity-laced signs," Trump said of his campaign manager.