His father, Frank Miller, was also a Progressive Conservative MPP from the region for 11 years, and briefly served as Premier of Ontario in 1985.

Miller started a Muskoka Young Progressive Conservative organization in 1975, and has been active in the party since this time.

Miller along with his wife Chris, and their children Abigail, Renne, Winston and Stuart owned and operated a lodge called Patterson Kaye between the 1980s until 2005.

Miller was re-elected by an increased margin in the 2003 provincial election, although the Progressive Conservatives were reduced to only 24 out of 103 seats in the legislature as the Liberals won a commanding majority.

[4] In 2004, he supported John Tory in the latter's successful bid to succeed Eves as leader of the Progressive Conservative Party.