Sen. Bernie SandersBernard (Bernie) SandersDems ponder gender politics of 2020 nominee 2020 Dem contenders travel to key primary states After Florida school shooting, vows for change but no clear path forward MORE (I-Vt.) on Saturday was quick to hit back at President Trump for tweeting that a rally of his voters would be bigger than any of the anti-Trump protests around the country.

"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!” Trump tweeted early Saturday.

"They did. It wasn't," Sanders tweeted alongside a photo of Trump's inauguration last month, next to a photo of former President Obama's 2009 inauguration, which drew a larger crowd.

Trump criticized the media for covering the crowd size at his inauguration, insisting that his crowd was bigger than Obama's 2009 crowd despite evidence to the contrary.

"We had a massive field of people, you saw that. Packed," Trump said during remarks at CIA headquarters last month.

"I get up this morning and I turn on one of the networks and they show an empty field. I said wait a minute, I made a speech, I looked out, the field was, it looked like a million, a million and a half people. They showed a field where there were practically nobody standing there," he added.

The day after Trump’s inauguration, White House press secretary Sean Spicer insisted his swearing-in was “the largest audience to witness an inauguration, period. Both in person and around the globe.” He claimed that the numerous photos showing Obama’s inauguration was larger were “intentionally framed … to minimize the enormous support.”