Donald Trump Jr. addresses the Republican National Convention in Cleveland in July. The Anti-Defamation League has called for Donald Trump's oldest son to apologize for making what purported to be a Holocaust-themed joke. (Scott Applewhite/AP)

Donald Trump Jr. says things. Lots of things. Sometimes, they are problematic things: At least twice this week he was forced to defend an action or remark viewed as racially or culturally insensitive.

Of course, not all of the remarks were initially his own words: He has often stumbled based on his social media decisions — the people he retweets and the messages he amplifies.

Let's recap:

The "gas chamber" comment

“The media has been her number-one surrogate in this," Trump said in a Wednesday interview with a Philadelphia radio station, referring to Democratic nominee Hillary Clinton. "Without the media, this wouldn’t even be a contest. But the media has built her up. They’ve let her slide on every indiscrepancy [sic], on every lie, on every DNC game trying to get Bernie Sanders out of this thing."

Then he added: "If Republicans were doing that, they'd be warming up the gas chamber right now."

After the media and the Clinton campaign noted that sounded a lot like a Holocaust reference, the Trump campaign put out a defiant response. By Friday morning, he had acknowledged a poor "choice of words" but accused the media of targeting him because it had run out of ways to attack his father.

He told ABC's "Good Morning America" on Friday morning that he might have used the wrong language, noting that he had previously used "electric chair" in the same formulation.

"I didn't say anything about the Holocaust," he said. "It was poor choice of words, perhaps. But in no way, shape or form was I ever even remotely talking about the Holocaust."

Posting Pepe the Frog on Instagram

After Clinton made her "basket of deplorables" comment and Trump supporters gleefully embraced the label, Trump this week sought to do the same. So he Instagrammed a mock-up of a "The Expendables" movie poster with his, his father's and his father's supporters' faces superimposed over the words "The Deplorables."

The problem: One of the superimposed faces was of Pepe the Frog, a symbol that has been co-opted by white supremacists and nationalists.

Trump said a friend sent it to him.

On "Good Morning America," Trump said he didn't know the frog was such a symbol. "If I'm glib — perhaps that's the case — I've never even heard of Pepe the Frog," he said. "I thought it was a frog in a wig. I thought it was funny. I had no idea that there's any connotation there."

Radio interview with a white nationalist

In March, he did an interview with James Edwards, a white nationalist radio host who prefers the term "pro-white advocate." In the past, Edwards has decried interracial sex as "white genocide" and said "slavery is the greatest thing that ever happened" to black people.

Trump said at the time that he didn't realize who was asking him questions.

Via Bloomberg Politics:

Trump Jr. said Wednesday that he was speaking to another radio host for a previously scheduled interview via telephone when, unbeknownst to him, Edwards chimed in with questions. “He was brought into the interview without my knowledge,” the 38-year-old executive vice president for the Trump Organization said in an interview with Bloomberg Politics. “Had I known, I would have obviously never done an interview with him.”

Retweeting a professor who writes about "white identity"

On Sept. 1, Trump Jr. retweeted alt-right movement leader Kevin MacDonald, who runs the Occidental Observer website. According to the site's mission statement, it is focused on issues of "white identity, white interests, and the culture of the West."

KevinMacDonald
(via Twitter)

MacDonald is the director of the American Freedom Party, which was founded by William Johnson. If that name sounds familiar, it's because he was the white nationalist running robo-calls in favor of Trump in the Republican primary who was briefly in line to be a Trump delegate from California.

MacDonald has often written about how anti-Semitism is a logical reaction to Jewish success.

Retweeting a false Twitter claim about a Nazi salute

You may remember the story of Trump apologizing for falsely claiming that a supporter of Sen. Bernie Sanders (Vt.) was posing as a Trump supporter doing the Nazi salute.

His source was apparently Vox Day, who sent a tweet alleging that the woman was Sanders supporter Portia Boulger. Trump retweeted this claim.

After Trump retweeted it, Boulger responded. And soon the actual woman in the photo identified herself as Birgitt Peterson.

Day himself wrote in a 2010 World Net Daily column about expelling minorities from places like Minneapolis and Detroit to reclaim "traditional white Anglo-Saxon Protestant culture." His blog features regular posts about white identity and culture, though he prefers not to be called a white nationalist.

The takeaway for Trump, maybe: Never retweet.