An easier way to go about it would be to give limited weighting to population. Say everyone gets one vote than additional vote at 500,000, 1M, 5M, 10M, etc. At the moment it seems completely unfeasible that Fiji (population 125,000) has the same voting power as England (population 33,500,000). It is a level of weighting that makes the US Senate seem fair by comparison and is by an extremely large margin the most unequal body in the world currently ITTL and OTL. You can tweak the number to maximize white vote while still diluting the extremely large Indian states like Uttar Pradesh.
I'd agree, this would be a much better and more reasonable idea. And eventually something will have to replace what is, as you point out, a frankly ludicrous way to try and run a global power which likes to think of itself as a democracy. The problem is it doesn't take into account the nature of the Empire as at 1911 (where I've developed the TL too), how its evolving and how it actually currently works. At the start of the TL in 1870, the Empire was run almost entirely by the British. The Dominions had control over their domestic affairs and where expected to maintain a militia large enough to deal with local uprising and hold the line if a foreign power invaded till the British forces arrived. The British controlled everything else. They ran it, paid for it and defended it, what they said went. Well more or less, Natal did manage to drag the British kicking and screaming into two wars they didn't want and New Zealand had a good go at doing the same at doing the same a few times (thwarted by the lack of a navy).
Things began to change with the start of the Long Depression in 1873. This sparked the Europeans and US to ramp up tariffs to protect their domestic industry. This produced possibly one of the most important changes ITTL. The British abandoned their previously scared cow of free trade. They replaced with a policy of encouraging industrial economic development in the Dominions, aiming to transform them from captive markets and resource suppliers toward being proper trade partners. The theory was if they got richer, they could buy more British widgets. Plus why invest money in expanding US and Europe industry, infrastructure etc when you can get pretty much the same return on the money if you invest it the Dominions to do the same thing and at the same time maybe get them to cough up a bit more cash to help pay for running the Empire.
And it worked or at least started too. It also ran smack into a certain US President by the name of James Blaine in the 1880s, who ran round doing things like annexing Hawaii, trying to force the British out of Latin American, threatening to annex Panama, breaking treaties with Canada, and openly trying to build a navy intended to slug it out with the RN. This very successfully made the Dominions extremely concerned about security. Thus the process of Imperial begun in the 1870s started picking up pace, with the Dominions willing to bend on things like tariffs in return for increased British commitment to security. There was never any master plan to build an Imperial Federation, lots of people talked about it, but nobody really actively pursued that goal. What actually happened was the Dominions wanted a bigger voice in Imperial affairs (initially regarding security and foreign policy in Asia and the Pacific), with the British willing to listen in an effort to get further economic integration.
This merry meandering evolution continued along its happy undirected winding way right on up to the turn of the century. At which time people started noticing the Imperial Federation everyone kept mumbling about might actually be possible and started thinking "hey maybe we should do something about that." But nobody could actually agree on what to do or even what this hypothetical Imperial Federation should look like, let alone trying to figure how to run it. All these things got constantly put in the ' too hard basket' and kicked down the road for some unspecified time called later. Meanwhile the wandering unguided evolution of the CW kept right on trucking, so that by 1911, in a very real sense the Imperial Federation actually exists, just no one has sat down and tried to figure out how it should be organised, administered or governed. Not as in trying to work out the best way it should be run, as in pretty much nothing about how it should be run has been worked out at all. And now the world is riding the Great War Express with the end of the line in sight and coming up real fast.
This is currently the focus of most peoples attention and the consensus is now is not the time to risk damaging Imperial unity trying to sort this all out. So how the Empire is run is the result of a chaotic unplanned process of evolution in response to ongoing events. In general terms, the broad outline of Imperial policy is hashed out by a process of compromise at the Imperial Conferences which happen every two years. The convention had developed that any decisions of an Imperial Conference required unanimous consensus before they were accepted (hand up who's figured out what's coming up next). The Dominions let the British take the lead in implementing those policies in consultation with the standing Imperial Council in London. This includes representation from all the Dominions along with a number of the more important British cabinet ministers. The Council is supported by a permanent secretariat consisting of senior civil servants and military officers drawn from both Britain and the Dominions. The Council is officially just an advisory body, but it would be a rather foolish British PM who'd ignore it. This system actually worked quite well, and glaringly obvious problems with were ignored as part of that "its too hard or not important enough right now, we'll sort it out later" attitude which had plagued the development proper constitutional arrangements since 1880 (the date of the first Imperial Conference).
Or at least that's how it was run until Wilfred Laurier and his Liberal government were elected in Canada late 1904. While the concept of an Imperial Federation had the support of the majority of the public in Britain and the Dominions by then, It was a very long way from unopposed. And Laurier and his party were some of those who opposed it. They wanted to cut out from the Empire, roll back Imperial Integration, and build closer ties with the US. So they very simply refused to cooperate. They dug their feet in and said no to pretty much everything., preventing any consensus being reached. While day to day the Empire kept functioning, when it came to long term planning, developing policy etc, it ground a screeching halt. And this was right when three major international crisis hit in four years, each of which had a real risk of triggering a Great War.
At that point what passed for an Imperial constitution amounted to the belief there was a set of Core Imperial Principles which represented the common shared values of the Empire. Only one of these supposed principles had ever been spelt out, dealing with the free movement of labour with the Empire . There were also seven so called Imperial Doctrines (later would be renamed Commonwealth Doctrines) and one so called Extension to the first of those Doctrines. These were a set of compromise solutions to specific issues which had cropped up over time worked out by compromise at an Imperial Conference, accepted only after everyone agreed to them (as with everything at an Imperial Conference) and acknowledged as good guide for dealing with similar problems in the future. None of them came close to covering this situation, and since Laurier refused to accept any new Doctrine which didn't make any further Imperial Integration impossible, and even then only in return for agreement to roll back much of what had already been achieved, there was no way of resolving the situation short scrapping the entire system and trying to start again. Which would have effectively given Laurier exactly what he wanted.
Eventually the situation was resolved and the obstructionism came to an end. Won't say how, spoilers lol. But that took three and a half years and by then the world was gripped by the third and most serious yet International crisis. Faced with the imminent outbreak of a Great War (now felt to be inevitable in the very near future even if was avoided this time), and a system so obviously broken along with it being almost a year until the next Imperial Conference (see below),, a quick and dirty bodge fix was needed. This was an agreement that if war broke out, some kind of massive text only conference call using the All-Red Line would be held before any decisions were made. And when the next Imperial Conference did happen, while everyone agreed that kind of obstructionism should never be allowed to happen again. But it was also felt given the ever increasing likelihood of war breaking out at anytime, time was of the essence. So the result was another bodge fix. The new Brisbane Doctrine states:
Decisions at an Imperial Conference should be made by unanimous consensus whenever possible. However one member of the Empire should not be able to block the clear majority consensus when achieved. The clear majority shall be regarded as a two thirds majority in regard to Imperial security or foreign affairs, with a simple sufficient in all other cases.
This is where the one member one vote comes from. Everyone can see how much of a bodge it is and nobody is expecting it not to be replaced eventually, when they finally get round to figuring out how to run things. But the decision was " It will do for now. we can fix it later." Yep nobody learnt a damn thing from the situation lol
* Yes the obvious solution of an extraordinary emergency Imperial Conference was very seriously considered, but various factors made it impossible
The other problem that you'll run into though is that just because a dominion is "white" as a whole doesn't mean that each constituent part is white. This will mostly apply to South Africa with the white population concentrated in the Cape and breaking it up will likely end up with non-white dominions being created. In fact I could see the push to break up South Africa come from the Zulu and Xhosa tribes that are numerous and still organized in this time period. I would also be interested in seeing demographics for North Australia, Saskatchewan and Manitoba in this time period. I would venture to say that even though non-whites are not a majority they are probably a very large minority in the regions.
All I can say is see above. the current Imperial system is so incredibly broken, anything is possible
I do agree though that long term a unified British commonwealth/empire will lead to the dissolution of the federations within that empire. There is no reason for "Canada" to exist when each province can look to its internal affairs and larger projects would be handled at the Imperial level. The same goes for Australia, United Kingdom, South Africa, Nigeria, and a host of others. It wouldn't surprise me to see dozens of new "dominions" created as the imperial core strengthens itself at the cost of the "middle"
With the proviso of again see above. I'd think it very likely. Its in the nature of central governments. And the balkanisation policy is working in India. It will be the first go to.