Donald Trump's been made to "feel the bern".
The US President took to Twitter to urge his supporters to hold a counter-rally against the hundreds of thousands who've protested his policies since he was inaugurated last month.
"Maybe the millions of people who voted to MAKE AMERICA GREAT AGAIN should have their own rally. It would be the biggest of them all!" he wrote.
Cue Bernie Sanders, who cut the President down in just four words: "They did. It wasn't."
Mr Sanders, who lost to Hillary Clinton in the Democratic primaries, used photographs taken during Mr Trump's inauguration ceremony, showing he had far fewer supporters than Barack Obama attracted at his inaugurations in 2008 and 2012.
Mr Trump has maintained his inauguration was the biggest in history with 1.5 million attendees. Crowd experts estimated the true figure was closer to 300,000.
"Feel the bern" was a catchphrase used by Mr Sanders' supporters in his failed bid for the Democratic nomination, and they were quick to revive it.
As of Sunday morning (NZ time), Mr Sanders' tweet had been retweeted 73,000 times - compared to Mr Trump's 20,000.