Career
Born in Mackay, he was a clerk on the Mackay Electricity Board before becoming involved in politics. From 1994 to 1995 he was a state organiser of the Australian Labor Party. In 1995, he was elected to the Legislative Assembly of Queensland as the Labor member for Mackay, replacing Editor Casey, a former ALP leader.
He served as a backbencher until he was named to the Beattie Ministry to replace the disgraced Gordon Nuttall as Minister for Primary Industries and Fisheries in December 2005.
He was given additional responsibility for Regional Development in 2009, and his title was recast as Minister for Primary Industries, Fisheries and Rural and Regional Queensland. In February 2011, his titled was again changed, this time to Minister for Agriculture, Food and Regional Economies
Mulherin was elected as Deputy Opposition Leader in the wake of the ALP"s heavy defeat at the 2012 election.
He barely held on to his seat of Mackay, a Labor stronghold for the better part of a century. He was one of only three Labor members elected from outside South East Queensland.
During the 2015 election campaign Mulherin announced his retirement citing family and health reasons but remained as Deputy Opposition Leader until polling day.