Besseling was elected as an independent member in the New South Wales Legislative Assembly for the seat of Port Macquarie; winning the seat in a 2008 by-election. The seat came open when the former member, independent Rob Oakeshott, resigned to make an ultimately successful run for the federal seat of Lyne. Besseling worked as a political adviser for his sometime rugby teammate Oakeshott for the previous three years. Besseling won the seat with 35.9 percent of the primary vote and 54.5 percent of the two-party vote. This was a significant drop from Oakeshott's last victory in 2007; at the time of his resignation, Oakeshott sat on a majority of 28.2 percent, the safest in the Legislative Assembly. Alby Schultz, the Liberal Member for Hume, was seen campaigning a few times for Besseling, referring to him as "the pick of the candidates". Similar support was provided from Bill Heffernan, a Liberal Senator, sparking anger and resentment within the federal coalition. In 2011 Besseling lost his seat to National Party candidate Leslie Williams, suffering a swing of 11 percent. It is suggested that his defeat was due to his association to Oakeshott, whose support kept the federal Labor government in office after the 2010 federal election. Port Macquarie had always been considered National heartland, and had been a comfortably safe National seat in "traditional" two-party matchups with Labor even when Oakeshott held it without serious difficulty as an independent. "Besseling's re-election campaign struck controversy when oil from his campaign bus caused an accident on the Oxley Highway that resulted in three people being seriously injured." Whilst police investigations were inconclusive, it was believed that sabotage was the most likely cause for the missing sump plug that caused the leak. The political environment was very heated at the time. Following his failure to win re-election, Besseling recommenced employment as a political advisor, working in the office of Rob Oakeshott.
Local government
In 2012, Besseling was directly elected as Mayor; and secured three other Councillors to the Port Macquarie-Hastings Council on his independent election ticket. Besseling was reelected Mayor in September 2016, but then resigned in May 2017 to become General Manager at Birdon Pty Ltd.
