The notion of separation of church and state, in the way the democrats are seeking to apply it, is misguided; it isn't even accurate to the intention in America of the founding fathers. Religion, specifically that of Christianity, was the foundation of America, and has had a significant impact on the legal system in Australia. The separation policy was to keep the government out of church affairs (given the failure in England with the national church), though not Christian morality out of politics. As you should be aware, Christian belief is not a private affair, but speaks to every element of a world-view in the construction of healthy and whole individuals, and society collectively, even whilst respecting the freedom of others to dissent. As such, these beliefs impact sociology, ethics/morality, politics, law, and yes, even science/biology.
All have beliefs, and these beliefs are central to morality. As such, to try and divorce beliefs from morality, which is central to government and policy, is misguided. There is no neutral moral ground. Whilst I agree that bribery and manipulation are invalid approaches by religious groups to sway political process, when issues of morality come up, it would be irresponsible for 'believers' not to speak up. As a wise man once said, "Righteousness exalts a nation." Wise, morally informed choices provide the greatest benefit to the greatest number of people. It seems to me that the Democrats are pursuing a negative, destructive agenda, one betraying intolerance to Christians, not essentially on behalf of the people as democracy would require, but rather to create a society where humanist values have full sway. This is a double standard. The Democrats need to rethink their position, and use your energy in pursuing change that will genuinely benefit Australia.