Trump Protester Fights Security ... Criminal Charges Loom (VIDEO)

Donald Trump's security got in a physical fight with a protester Thursday, and campaign honchos say they will probably press criminal charges.

It happened outside Trump Towers in NYC ... Mexican immigrant Efrain Galicia took license with Trump's campaign slogan, trading the word "great" for "racist."

The video -- shot by NY1 Noticias -- shows the confrontation. Trump's people say a security guard was attacked from behind.