Donald Trump didn't waste any time responding to President Biden calling his supporters "garbage" ... joking that Biden's so old he doesn't even know what he said.
Trump was on stage Tuesday at a rally in Pennsylvania when he was told about Biden's inflammatory statement ... with Florida Senator Marco Rubio playing messenger boy.
The former president's first reaction was that Biden's diss was "terrible" ... then he compared the comment to Hillary Clinton calling Trump supporters "deplorable" and "irredeemable" during the 2016 election .... with Trump saying Biden's comment was worse.
As we reported, Biden was on a video call Tuesday when he said, "Donald Trump has no character. He doesn't give a damn about the Latino community … just the other day, a speaker at his rally called Puerto Rico a floating island of garbage? … The only garbage I see floating out there is his supporters."
While the White House tried to walk back the statement, claiming Biden was only talking about Trump and the comedian who made the Puerto Rico joke, Trump was quick to pounce ... calling Biden's mental capacity into question.
Trump jokingly told the crowd ... "Please forgive him, for he not knoweth what he said. ... Terrible to say a thing like that, but he really doesn't know. He really, honestly, he doesn't."
Vice President Kamala Harris, meanwhile, is distancing herself from Biden's comment, telling reporters today ... "I strongly disagree with any criticism of people based on who they vote for. You heard my speech last night, and continuously throughout my career. I believe that the work that I do is about representing all the people, whether they support me or not."