Acting prime minister is still a long way from the top, Boris Johnson | Michael White

Deputies may come very close to ultimate power, but as history shows, though some attain it for themselves, many more fall by the political wayside

The New York-born scholar Boris Johnson, currently billed as “acting prime minister” while Theresa May walks in the Swiss mountains, will know the only famous remark attributed to John Nance Garner. The sharp-tongued Texan, who had the misfortune to be Franklin D Roosevelt’s vice-president during the great man’s first two terms, once observed that the number two job wasn’t worth “a bucket of warm spit”.

Sometimes it’s quoted as a pitcher’s worth, sometimes a quart, occasionally the liquid in question is warm piss. But everyone gets Garner’s drift: he regretted taking the job. Roosevelt’s next veep, Henry Wallace, got dropped for being leftwing. The one after that lucked out. Unassuming Harry Truman succeeded to the Oval Office when the ailing president died three weeks before Hitler in April 1945. In August he got to drop the bomb.

Related: 'Avoid diplomacy': five guidelines to help Boris Johnson run the country

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