President Trump on Monday urged Democrats to “loosen up and have some fun,” criticizing the party for being “self righteous and ANGRY.”

The Democrats are so self righteous and ANGRY! Loosen up and have some fun. The Country is doing well!

— Donald J. Trump (@realDonaldTrump) February 11, 2019

It’s unclear what prompted Trump’s tweet, though multiple Democrats over the weekend made clear their presidential aspirations for 2020, and called out the president in the process.

{mosads}Sen. Elizabeth Warren (D-Mass.) officially entered the 2020 campaign on Saturday, and called Trump a “symptom of what’s gone wrong in America.”

In Iowa on Sunday, Warren was harsher in her criticism of Trump, suggesting that by the time of the 2020 election, he “may not even be president” or “may not even be a free person,” citing the multiple investigations into those close to him.

Sen. Amy Klobuchar (D-Minn.) declared her candidacy from snowy Minneapolis on Sunday. Though she did not explicitly mention Trump, she took a few veiled shots at the president. She pledged to press a number of pro-environment initiatives if elected, and vowed not to conduct “foreign policy by tweet.”

After Trump tweeted that Klobuchar “looked like a Snowman” during her announcement, the senator responded by asking how Trump’s hair “would fare in a blizzard?”

The president targeted Democrats repeatedly on Twitter over the last few days, chiding Warren’s campaign, mocking the Green New Deal proposal backed by some party members and criticizing the party for its stance in ongoing border security funding negotiations.

Trump is set to hold his first campaign rally on Monday since last year’s midterm elections. He will travel to El Paso, Texas, to speak near the border as he continues his push for a border wall.

Former Rep. Beto O’Rourke (D-Texas), who is mulling a 2020 bid, will hold a counter-rally at the same time.