Chief Clown chief contender is well-known Oompa Loompa, Bill Shorten (below: Bill shares a joke with senior ACTU colleagues at the 2012 Congress).
This happy news also appears at Quadrant OnLine, but you don't get the full Joe Miller of the ACTU thing unless you can see the full photo.
Check out the guy on the far right. Is it Bill Ludwig? Answers on the back of a postcard, please.