[3] Nahan entered politics at the 2008 Western Australian state election when he defeated incumbent Labor MP Tony McRae for the seat of Riverton in southern Perth.

Nahan served as the Trustee of the Parliamentary Superannuation Board and was Chairman of the Economics and Industry Standing Committee in State Parliament from November 2008 to August 2012.

It was later determined that the fire was caused by an out of control prescribed burn being conducted by FESA, El Questro, the WA Police and the James Gino Salerno family, a cult residing around Kununurra.

After the Liberal/National government was reelected at the 2013 Western Australian state election, Nahan was promoted to cabinet as Minister for Energy, Finance, and Citizenship and Multicultural Interests by Premier Colin Barnett.

[10] Nahan has been compared to Ned Flanders, a character from The Simpsons, with The West Australian cartoonist Dean Alston drawing him in the style of the animated television show.

Despite being a member of the Western Australian Legislative Assembly since September 2008 and Treasurer in the Barnett Government for three years, this possible liability was only disclosed in 2018 during a debate over eligibility of dual citizens.

Nahan is reported to be one many thousands of U.S. citizens caught up in the changes and is awaiting the outcome of several court cases in the United States where lawyers are confident that, if successful, his liability will be expunged.