Most remember JBJ's legacy was significant because he was the first opposition candidate to win a seat since Singapore's independence. That year was 1981 when he won the Anson by-election.
Few remember that JBJ did so despite a 3CF. Even fewer remember the candidate which nearly prevented JBJ from winning. Those who do remember Harbans Singh as a spoiler whose vote share of less than 2% consigned him and his party to oblivion forever.
Had JBJ lost and PAP won, a certain Kenneth Jeyaretnam would not only be a total political unknown in Singapore, he would be unable to hang JBJ's legacy on his lips as he would often do.
Ironically, 32 years later, KJ became the spoiler who nearly prevented another candidate from walking his father's footsteps. As it turned out, his opponent became the second opposition candidate to snatch a seat from PAP at a by-election, standing under the same party as his father then, one his father led for 30 years. His vote share of less than 2% consigned him and the party founded by his father in the same direction of his father's then-opponent.