Joseph P. Kennedy, Sr. (1888-1969) took a low profile in the 1960 presidential election; only after his son, John F. Kennedy, won the election did both father and son appear in photographs together. The New York (NY) Times printed on January 8, 1961 that Joseph Kennedy said his new public face was no accident:
 
“There are no accidents in politics. There is no contest any more, I can appear with him any time I want to now.”
 
Although Joseph Kennedy popularized “there are no accidents in politics,” it had been said before 1960. Abolitionist minister Theodore Parker (1810-1860) said in 1848, “They called him (John Tyler—ed.) an accident; but there are no accidents in politics.”
   
A similar saying (incorrectly credited to Franklin D. Roosevelt) is “In politics, nothing happens by accident. If it happens you can bet it was planned that way.”
   
 
Wikipedia: Joseph P. Kennedy, Sr.
Joseph Patrick “Joe” Kennedy, Sr. (September 6, 1888 – November 18, 1969) was a prominent American businessman, investor, and ambassador. Kennedy was an Irish American and was the father of U.S. President John F. Kennedy, United States Attorney General and Senator Robert F. Kennedy, United States Senator Edward M. Kennedy, naval officer Joseph P. Kennedy, Jr., Special Olympics co-founder Eunice Kennedy Shriver, and former U.S. Ambassador to Ireland Jean Kennedy Smith; and the grandfather of U.S. Representatives Joseph P. Kennedy II and Patrick J. Kennedy. He was a leading member of the Democratic Party and of the Irish Catholic community. He was the inaugural Chairman of the U.S. Securities and Exchange Commission (SEC), appointed by President Franklin D. Roosevelt (FDR), and later directed the Maritime Commission. Kennedy served as the United States Ambassador to the United Kingdom from 1938 until late 1940, including the early part of World War II.
 
Born to a political family in Boston, Massachusetts, Joseph P. Kennedy, Sr. was educated at Boston Latin School and Harvard University, and embarked on a career in finance, making a large fortune as a stock market and commodity investor and by investing in real estate and a wide range of industries.
 
John F. Kennedy Presidential Library and Museum
Quotations of Joseph P. Kennedy
(...)
“There are no accidents in politics.” Remark to a reporter, 1960.
 
Google Books
Speeches, Addresses, and Occasional Sermons
Volume 2
By Theodore Parker
Boston, MA: Wm. Crosby and H. P. Nichols
1852
Pg. 107:
SPEECH AT FANEUIL HALL, BEFORE THE NE ENGLAND ANTI-SLAVERY CONVENTION, MAY 31, 1848.
Pg. 109:
During one term, the chair was filled by an amphibious presidency, by General Harrison, who was nothing but a concrete availability, and John Tyler, who was — John Tyler. They called him an accident; but there are no accidents in politics.
 
Google Books
24 October 1914, The California Outlook (A Progressive Weekly), “Hiram Johnson in Private Life and Public Service,” pg. 8, col. 1:
There are no “accidents” in politics.
 
8 January 1961, New York (NY) Times, Joseph Kennedy Is Back on Scene After Seclusion in the Campaign; President-Elect’s Father Says Change Is No Accident—He Thought It Discreet Not to Embarrass Son’s Advisers” by Ira Henry Freeman, pg. 36:
Change of Public Face
With his usual candor, Joseph Kennedy said last Friday that his change of public face was no accident—“there are no accidents in politics.” He did think it discreet to absent himself from his son’s campaign, but since “there is no contest any more, I can appear with him any time I want to now.”
 
Google Books
The Founding Father:
The Story of Joseph P. Kennedy
By Richard J. Whalen
New York, NY: New American Library
1964
Pg. 463:
After their long public separation, the press noted that father and son suddenly seemed to be together almost constantly. When a reporter asked whether this was just coincidental, Joe Kennedy’s terse reply was epigrammatic. “There are no accidents in politics,” he said. “I can appear with him any time I want to now.”
   
Google Books
The Sins of the Father:
Joseph P. Kennedy and the Dynasty He Founded
By Ronald Kessler
New York, NY: Grand Central Publishing
2012
Pg. ?:
When Joe awoke in Hyannis Port on November 9, 1960, Jack had been elected president by a margin of a tenth of one percent. For Joe, it as the culmination of a lifetime of effort.
 
“There are no accidents in politics,” he said. “I can appear with him any time I want now.”