That first Commonwealth Parliament was elected by State voters but when it met it had to decide who should be entitled to vote for it in future. Three groups attracted debate. Women had votes in some States but not in others, so had Aborigines. And there were some Chinese, Indian and other non-white people who had become permanent residents before the introduction of the White Australia immigration policy.
The debates reflected the racist temper of the times with references to savages, slaves, cannibals, idolaters and Aboriginal 'lubras' and 'gins'. The Senate voted to let Aborigines vote but the House of Representatives defeated them. The 1902 Franchise Act gave women a Commonwealth vote but Aborigines and other 'coloured' people were excluded unless entitled under section 41 of the Constitution.
Section 41 said that anyone with a State vote must be allowed a Commonwealth vote. South Australia got that clause into the Constitution to ensure that South Australian women would have Commonwealth votes whether or not the Commonwealth Parliament decided to enfranchise all Australian women. The Commonwealth did enfranchise all women so they did not need section 41. But that section did seem to guarantee that, except in Queensland and Western Australia, Aborigines would be able to vote for the Commonwealth because of their State rights.
But did it mean that? The first Solicitor-General, Sir Robert Garran, interpreted it to give Commonwealth rights only to people who were already State voters in 1902. So no new Aboriginal voters could ever be enrolled and, in due course, the existing ones would die out. The joint Commonwealth/State electoral rolls adopted in the 1920s give some idea of the number of Aborigines who voted for their State parliaments but were barred by the Commonwealth. The symbol 'o' by a name meant 'not entitled to vote for the Commonwealth' and almost always indicated an Aborigine.