A Campbell Soup Company executive who had planned to retire next month left last week instead after sharing a conspiracy theory on Twitter about a migrant caravan in Mexico, the company said on Monday.

Campbell said the company and the executive, Kelly Johnston, the vice president of government affairs for 16 years, had agreed to “accelerate” his retirement after he said on Twitter last week that a foundation led by George Soros, the billionaire philanthropist and liberal activist, was the driving force behind a caravan of thousands of migrants headed toward Mexico’s border with the United States.

Mr. Soros’s activism has made him a lightning rod for criticism among some conservatives and right-wing activists. Last week, a pipe bomb was delivered to his house in Westchester County, N.Y. It was one of 14 explosives sent to people who are regularly disparaged by the right. The authorities have charged an outspoken supporter of President Trump with sending the bombs.