Presidential frontrunner Joe Biden had a strong closing statement, until he fumbled his digital outreach and inspired an avalanche of bipartisan mockery on social media.

Biden went after President Donald Trump in a series of scathing critiques, but when it came to the very last few words when he was to tell supporters how to contact the campaign, he flubbed it.

"If you agree with me, go to Joe, three, oh, three, three, oh," he said, sounding unsure of himself, "and help me in this fight."

Social media erupted with jokes over the gaffe.

The confusion appeared to come from other candidates giving out web addresses, while Biden was to ask supporters to text a number on their phones.

Here are some of the reactions:

Eventually, the Joe Biden social media account clarified what he meant to say: