GOP front-runner Donald Trump deleted a retweet dissing early voters in Iowa Thursday, a rarity for the active Twitter user.

Trump took to Twitter to say a “young intern” accidentally “did a Retweet” and has apologized.

The young intern who accidentally did a Retweet apologizes. — Donald J. Trump (@realDonaldTrump) October 22, 2015

Trump had quote-retweeted a tweet linking his recent drop in Iowa polls to the state’s genetically modified corn. The tweet speculated that Iowa voters had “issues in the brain.”

Trump deleted the tweet, but TPM captured a screenshot:

It was a rare move for the ex-reality TV star, who’s an active user of Twitter and Instagram. Trump has often taken heat for his bluntness online, but some of his most off-color tweets, which are often resurfaced by his opponents and the media, largely remain live.