The tweet revealed a President still reverting to his old social media habits, namely, those likely to earn him quick criticism, less than two months after retired Gen. John Kelly took over as White House chief of staff.
While Kelly has not sought to stop Trump from tweeting, he has encouraged the President to allow him to vet the tweets before posting them -- a request Trump has sometimes acquiesced to.
The White House did not respond to a request for comment Sunday about the President's tweet and whether Kelly was aware of it.
A spokesperson for Hillary Clinton declined to comment on the tweet.
The Twitter user Trump retweeted, @Fuctupmind, frequently posts pro-Trump messages and memes, but has also used the platform to disparage transgender individuals and Jews.
"Please get rid of the Hasidic Jews. They are the worst people on the planet. They have taken over areas in NY," the account tweeted last November, according to Buzzfeed News. The tweet has since been deleted.
"The President of the United States just retweeted a video vignette that imagines him assaulting his political rival. The man is unfit," tweeted Shaub, who joined the ethics office as a staff attorney early during the George W. Bush administration and was appointed as the office's director by President Barack Obama.
The tweet, which came as Trump prepares to head to New York for a critical round of powerhouse diplomacy with world leaders at the United Nations, followed a week during which Clinton reemerged in the spotlight as she promoted her new book, "What Happened," about the 2016 campaign, reviving her fiercest criticisms of Trump and his supporters and reigniting the debate about her stunning, unanticipated loss.
Trump slammed Clinton over her new book earlier this week too, tweeting that she "blames everybody (and every thing) but herself for her election loss."
Trump's Sunday morning Twitter post was one of more than a half-dozen supporters' tweets the President retweeted Sunday before 8:30 a.m.
Those other tweets included an image predicting Trump would win every state for reelection in 2020, another showing Trump hauling US companies that have outsourced manufacturing abroad and a tweet claiming that "only true Americans can see that president Trump is making America great."
Trump has promised to rescind protections for those undocumented immigrants and said during the campaign they would have to be deported. Grassroots conservative supporters of the President also fumed that Trump would grant legal status to those undocumented immigrants without securing funding for the border wall, which he continues to promise will be built despite a lack of support in Congress.
Trump also took to Twitter Sunday morning to tweet about his call late Saturday night with South Korean President Moon Jae-in to discuss the ongoing tensions with North Korea over its nuclear and ballistic missile programs.
"I spoke with President Moon of South Korea last night. Asked him how Rocket Man is doing," Trump tweeted, appearing to offer a new moniker for North Korean dictator Kim Jong Un. "Long gas lines forming in North Korea. Too bad!"
Both leaders' offices said Trump and Moon pledged during their call to work with the international community to ramp up pressure on the North Korean regime, which has so far been undeterred in advancing its nuclear and ballistic missile program despite a tightening of international sanctions.