For close to two decades, Tengku Adnan Tengku Mansor was indomitable in Putrajaya. However, the veteran politician tasted defeat in the last general election, falling to Perikatan Nasional’s Radzi Jidin in a multi-cornered battle.

The seat, which encompasses the federal administrative capital, was regarded as a safe deposit for the government.

More than seven months later, Tengku Adnan claimed his...