Donald Trump slammed Sen. Elizabeth Warren’s official 2020 presidential announcement on Saturday, mocking her claims of Native American ancestry in a tweet claiming that Warren would run as the country’s first potential “Native American presidential candidate.”

In the tweet posted hours after Warren’s presidential campaign announcement earlier in the day, Trump joked that he would “see [Warren] on the campaign TRAIL,” which many said was a reference to the “Trail of Tears” forced relocation of Native American tribes that led to the death of as many as 8,000 Cherokee between 1830 and 1850.

“Today Elizabeth Warren, sometimes referred to by me as Pocahontas, joined the race for President. Will she run as our first Native American presidential candidate, or has she decided that after 32 years, this is not playing so well anymore? See you on the campaign TRAIL, Liz!” he wrote.

Today Elizabeth Warren, sometimes referred to by me as Pocahontas, joined the race for President. Will she run as our first Native American presidential candidate, or has she decided that after 32 years, this is not playing so well anymore? See you on the campaign TRAIL, Liz!

— Donald J. Trump (@realDonaldTrump) February 9, 2019

Twitter quickly slammed Trump for making an insensitive joke referencing a painful time in American history, the forced relocation of Native American tribes, known as the Trail of Tears.

Some noted that the president openly admires Andrew Jackson — who made the removal of Native Americans from their land a top legislative priority — so he likely knew exactly what he was doing when he wrote in all-caps “TRAIL.”

Others noted Trump’s tweet was “another racial flareup.”

Read what they are saying on Twitter below:

Thousands of Native Americans died on the Trail of Tears, which Trump appears to be jokingly referencing here https://t.co/zfM6SSUxCs

— Cristiano Lima (@viaCristiano) February 9, 2019

This person could not be more grotesque or spiritually sick https://t.co/rn2q2vk9HU

— Seth Abramson (@SethAbramson) February 10, 2019

Our president is officially making openly racist jokes on twitter that would get anyone else kicked off of Twitter. https://t.co/Eigix0YRCb

— Amee Vanderpool (@girlsreallyrule) February 10, 2019

This may sound obvious, but given that Democrats have been calling for Ralph Northam to resign over being racist 35 years ago, maybe we should hear some more prominent voices calling on the President to resign for being racist an hour ago https://t.co/r5oJQzuXja

— Brandon Friedman (@BFriedmanDC) February 10, 2019

4000 Native Americans died on the Trail of Tears due to forced relocations under the Andrew Jackson administration. Trump decided to honor Navajo code talker vets in front of Andrew "Indian Killer" Jackson's portrait last year because of course. Now this… https://t.co/XbXGnlRS5J

— Wajahat Ali (@WajahatAli) February 10, 2019

Trump is one of the most racist presidents we've ever had & he doesn't even own slaves. You'd think it'd be hard to break into the Top 10 if you didn't own people or slaughter Native Americans but he somehow manages it. https://t.co/fYkej6RAux

— Stephen Robinson (@SER1897) February 9, 2019

This motherfucker actively admires Andrew Jackson.

He knows EXACTLY what he's saying when he "jokes" about the Trail of Tears. https://t.co/LqrEjd9cS1

— Emily Crockett (@emilycrockett) February 10, 2019

Trump’s eldest son, however, had quite a different take on the whole thing.

“Savage!!! Love my President,” Donald Trump Jr. wrote on Instagram, including a screenshot of his father’s tweet, along with Michael Malice’s commentary.

View this post on Instagram

Savage!!! Love my President.

A post shared by Donald Trump Jr. (@donaldjtrumpjr) on Feb 9, 2019 at 3:44pm PST