What political agenda? The Mardi Gras is a huge social event and attracts a lot of people - last year over 300,000 watched the parade:
Mardi Gras 2016: Glitter explosion in Sydney's Oxford Street as thousands attend parade - ABC News (Australian Broadcasting Corporation)
It's clearly a big deal tourism-wise:
"In 2015, more than 23,000 interstate and international visitors travelled to Sydney for the annual Mardi Gras Parade and to take part in some of the festival's series of events"
Unforgettable Experiences Mardi Gras l Qantas