The president's son took aim at the former mayor of New York City's performance during the Democratic debate in Las Vegas.
The president's eldest son also said he believed his father's critics would say the president had dementia if he mixed up states.
The president's eldest son suggested the former New York City mayor did not have a "real following" and had to buy support.
Tim O'Brien told the president's eldest son that his father was a "flagrantly hateful racist" and said his boss was not "in the same category."
The president's eldest son has not ruled out a future presidential run and came second in a poll of possible 2024 candidates earlier this year.
Donald Trump Jr. took to Twitter Wednesday to blast House Speaker Nancy Pelosi tearing up a copy of his father's State of the Union speech, while praising GOP Senators for shredding "her impeachment."
In a Wednesday tweet, Donald Trump Jr. called for the removal of Utah Senator Mitt Romney from the GOP after Romney announced he would vote to convict President Donald Trump on the abuse of power charge leveled against him in his impeachment trial.
"Pete had the ability to actually campaign for the last few weeks while Bernie was stuck in DC because of Nancy's nonsense," the president's eldest son said.
Safari Club International is offering a 7-day hunting trip to Alaska with Donald Trump Jr. and one of his sons; the current bid is $10,000.
The musician urged fans to sign a petition asking Mike Love to reconsider a planned performance on Wednesday.
The heckler—an organizer for progressive Jewish American group IfNotNow—accused Donald Trump Jr. of spreading anti-Semitic conspiracy theories.
Journalist Andrea Bernstein said that the two Trump children were well aware of the wrongdoing that prompted allegations of fraud against them in the 2000s.
"Yesterday's action vs the disgraceful response at Benghazi is all you need to know about leadership then & now!" the president's eldest son said.
After Donald Trump Jr. approvingly linked to an article which called the removal of President Trump's cameo in the Canadian Broadcasting Corporation's airing of 'Home Alone 2' "pathetic," the network replied that the version they aired had excised Trump's cameo long before he ran for office.
Trump Jr., a fierce defender of his father, called the impeachment of his father a "partisan sham."
Richard Painter, a Bush White House lawyer, tweeted that the Trumps are "an organized crime family," after telling MSNBC they should all be prosecuted.
Two people were killed last week when an Islamic extremist launched a knife attack in central London.
Donald Trump Jr. tweeted that an airport bookseller has not stocked his 'Triggered' book, prompting his supporters to complain on the bookseller's social media account.
With about 1.1 million Americans living with HIV, and no outright cure on the horizon, is the United States anywhere close to eradicating the virus?
The identity of the anonymous author behind a tell-all book on the Trump administration may soon be revealed.
Farrow tweeted the image on Tuesday, writing: "@realDonaldTrump tell your sons that animal cruelty is now a crime."
Newsweek analysis found that Trump Jr. referred to 30 separate articles from news outlets that have been dubbed "fake news" or otherwise attacked by himself or his father.
Tony Schwartz, who co-authored President Donald Trump's 1987 book, said the U.S. leader, his children Ivanka and Don Jr., and son-in-law Jared Kushner, should be behind bars.
Lara Trump could win or "at the very least it would be very competitive," retiring Republican Congressman Peter King said.
The comedian dissected what he says is Republicans' strategy to obfuscate their way out of the impeachment inquiry.
The poll also found South Bend Mayor Pete Buttigieg leading the pack of Democratic candidates in Iowa.
George Conway and Donald Trump Jr. exploded in a Twitter fight Friday during the testimony of former U.S. Ambassador to Ukraine Marie Yovanovitch at the Trump impeachment hearings.
Local media outlets reported that they were not even allowed to conduct interviews with people on the warehouse's premises.
Guardian journalist Andrew Gumbel said the room was so loud with chants and booing that he could hear "only half" of what microphones picked up.