Dermer was re-elected at the 2001 and 2005 state elections, and held the position of government whip in the Legislative Council from May 2001 to September 2008, and opposition whip from then until his retirement in May 2013.[2]
Dermer was one of the three North Metropolitan Labor MLCs, including Graham Giffard and Ken Travers, who were critical to the introduction of daylight saving in Western Australia in 2006. Initially intending to vote against the move, they all eventually decided to support it, in line with the wishes of their electorate and party.[3]
In 2008, Dermer was caught in a rip current with his sons, Alexander and Cameron, while holidaying at a Surfers Paradise beach. Dermer and Cameron had to be rescued by lifesavers. Not long after that, Dermer was diagnosed with a melanoma on the back of his neck, which was removed and found to be malignant.[4]