The trouble ain’t that there is too many fools, but that the lightning ain’t distributed right.

Mark Twain (1835-1910) American writer [pseud. of Samuel Clemens]

Quoted in Merle Johnson, ed., More Maxims of Mark (1927)
    (Source)

Not found in a primary source. Johnson was a rare book collector who published the first thorough bibilography of Twain's works in 1910. His 1927 work is a 15-page pamphlet, generally considered authentic by scholars, but it provides no other context for the saying.

For more information on the history of this quotation, see Quote Origin: The Trouble Ain’t That There Is Too Many Fools, But That the Lightning Ain’t Distributed Right – Quote Investigator®.

Variant: "The trouble isn’t that there are too many fools, but that the lightning isn’t distributed right."