Dean Smith was 30,000 feet high when the ground shifted beneath him.



It was the day after the Sydney siege and Smith, a Western Australia Liberal senator, was flying from Perth to Albany. He had primary schools to visit and army veterans to meet – routine duties to fulfil on a day drenched in sorrow.



Opening his newspaper, he read about Tori Johnson, the Lindt cafe manager who died in the siege, leaving behind a male partner of 14 years.



Smith – the first openly gay federal parliamentarian in Liberal Party history – doesn't presume to know Johnson's politics or his views on gay marriage. But, as he reflected on the tragedy, his thoughts turned to a question he thought he had resolved years earlier.



"If they had wanted to get married, that opportunity was denied to them until the day of the siege and is now lost to them because Tori Johnson is no longer here. When that dawned on me I was overcome with a lot of sadness because that's something I could help correct," he says.



When Smith entered the Senate in 2012, gay marriage advocates hoped they had found a conservative champion for their cause. They were wrong.



"I reject the suggestion of marriage equality," he said during a 2012 debate on gay marriage. "The claim to equality ignores the widely accepted fact that marriage is an institution that has a long and well-accepted definition – a definition that is heavily laden with cultural meaning and values crafted by custom and by law over the years."



Smith is one of the proudest traditionalists in federal politics. A signed portrait of Queen Elizabeth hangs in his Parliament House office, reflecting his passion for the monarchy. He cherishes the Australian flag and he's a devout Protestant.

"I believe in God. I believe in the biblical story of the crucifixion and the resurrection. I pray."

Western Australia Liberal Senator Dean Smith is Australia's first openly gay Liberal Member of Parliament. Credit:Philip Gostelow

He has always opposed gay marriage – or had until that December day.

"The fact Tori Johnson was a gay man in a long-term relationship made the event resonate more powerfully for me. These tragic circumstances happen and they make us reflect on our long-held positions and attitudes," he says.