Why did Peter Dutton Press the Nuclear Button

I previously stated that Australian opposition leader Peter "potato" Dutton had already lost the next election, over a year out. This was for a number of reasons - a major one being his re-igniting of the climate change wars with his take it or leave it mandate for nuclear power, but why did he commit such a brazen act of political suicide? And this in an era where opposition leaders try to stand for as little as possible as close as possible to their opponent, standing for something massive and putting all the attention on yourself is borderline insanity - surely mummy Gina Rinehart isn't THAT powerful?