From Father to Son, the Prime Ministers of Singapore

Singapore
The Current and 3rd Prime Minister of Singapore since 12 August 2004, Mr Lee Hsien Loong is the eldest son of the 1st Prime Minister (from 1959 to 1990), Mr Lee Kuan Yew.
By influence or by merit ? people questioned.
And what about the followings :

USA
John Quincy Adams (July 11, 1767 – February 23, 1848) was the sixth President of the United States from March 4, 1825 to March 4, 1829. He was the son of the second President John Adams.

Benjamin Harrison (August 20, 1833 – March 13, 1901) was the 23rd President of the United States. He was a grandson of the ninth President of the United States William Henry Harrison.

George Walker Bush (born July 6, 1946) was the 43rd President of the United States from 2001 to 2009. He is the eldest son of George H. W. Bush (the 41st President).

India
Jawaharlal Nehru was the first Prime Minister of Independent India.

Jawaharlal Nehru’s daughter, Indira Priyadarshini Gandhi nee Nehru (19 November 1917 – 31 October 1984) was the Prime Minister of the Republic of India for three consecutive terms from 1966 to 1977 and for a fourth term from 1980 until her assassination in 1984, a total of fifteen years. She was India's first and, to date, only female Prime Minister.

Rajiv Ratna Gandhi (20 August 1944 – 21 May 1991), the elder son of Indira Priyadarshini Gandhi, was the 7th Prime Minister of India from his mother's death on 31 October 1984 until his resignation on 2 December 1989 following a general election defeat. He became the youngest Prime Minister of India when he took office (at the age of 40).

Japan
Morihiro Hosokawa (細川 護煕 Hosokawa Morihiro, born January 14, 1938) was the 79th Prime Minister of Japan from August 9,1993 to april 28, 1994. He is the grandson of former Japanese Prime Minister Fumimaro Konoe.

Malaysia
Dato Seri Mohd. Najib bin Tun Haji Abdul Razak (born July 23, 1953) is the sixth and current Prime Minister of Malaysia. He is the son of Malaysia's second prime minister, Tun Abdul Razak.