British writer Ernest Benn (1875-1954) has been quoted from 1930: “Politics is the art of looking for trouble, finding it whether it exists or not, diagnosing it incorrectly and applying the wrong remedy.”
 
American comedian Groucho Marx (1890-1977) is often credited with “Politics is the art of looking for trouble, finding it everywhere, diagnosing it incorrectly, and applying the wrong remedies,” but there is insufficient evidence that he ever said it.
 
   
Wikipedia: Ernest Benn
Sir Ernest John Pickstone Benn, 2nd Baronet (25 June 1875 – 17 January 1954) was a British publisher, writer and political publicist. He was an uncle of the Labour politician Tony Benn.
 
Benn was born in Oxted, Surrey. As a civil servant in the Ministry of Munitions and Reconstruction during the First World War he came to believe in the benefits of state intervention in the economy. In the mid-1920s, however, he changed his mind and adopted “the principles of undiluted laissez-faire”.
 
From his conversion to classical liberalism in the mid-1920s until his death in 1954 Benn published over twenty books and an equivalent amount of pamphlets propagating his ideas. His The Confessions of a Capitalist was originally published in 1925 and was still in print twenty years later after selling a quarter of a million copies. In it he rejected the labour theory of value and argued that wealth is a by-product of exchange.
       
27 July 1930, Springfield (MA) Republican, pg. 10A, col. 3:
A CYNIC’S DEFINITION
[Sir Ernest Benn.]
Politics is the art of looking for trouble, finding it whether it exists or not, diagnosing it incorrectly and applying the wrong remedy.
 
Google Books
What Is Truth
By Henry Powell Spring
Winter Park, FL: Orange Press
1944
Pg. 31:
POLITICS IS THE ART OF LOOKING FOR TROUBLE; FINDING IT EVERYWHERE, DIAGNOSING IT WRONGLY, AND APPLYING UNSUITABLE REMEDIES. — SIR ERNEST BENN.
   
New York (NY) Times
8 September 1946, New York (NY) Times, “Cynics on Politics,” pg. SM16:
“Politics is the art of looking for trouble, finding it everywhere, diagnosing it wrongly, and applying unsuitable remedies.”—Sir Ernest Benn. 
 
Google News Archive
8 April 1953, Milwaukee (WI) Sentinel, “Today’s Chuckle,” pg. 1, col. 7:
Politics is the art of looking for trouble, finding it everywhere, diagnosing it wrong and applying unsuitable remedies.
 
Google News Archive
9 November 1964, Kentucky New Era (Hopkinsville, KY), “Try and Stop Me” by Bennett Cerf, pg. 4, col. 3:
“Politics is the art of looking for trouble, finding it everywhere, diagnosing it incorrectly, and applying the wrong remedies.”—Groucho Marx.