The people of the dominions would have supported it because they regarded themselves as British and the British Empire as their country.
New Zealand and Australia where even reluctant to have defence and foreign affairs powers placed on their shoulders at the time.
No one in any dominion let alone Britain would accept India as part of a British Imperial Union with voting power.
The British people would not wish to be ruled by Indians as much as the Indians didnt want to be ruled by the British.
As for the wealth India was on par in GDP with the White Dominions but vastly lower and more costly in terms of GDP per head.
Your next problem is that in your understanding of the OTL, you confuse history with mythology.
He only won one General Election but then again he only fought two.
If he stayed on he would have won more.
In Feb 1945 many Conservatives became well aware that Labour had an 18% poll lead.
Churchill's approval ratings however stood at 83%.
Had Churchill pushed more on the social reform front and got the left out of the BBC and propaganda arms of the government plus this idea of a British Imperial Union he may well have won the election.
Churchill fought THREE general Elections: 1945, 1950 and 1951. The last TWO were against a Labour party that was worn out, and beginning to descend into a civil war that lasted most of the 50s. Incidentally, even in 1951, Labour got more votes! The Conservatives won because they won more seats (although Labour did the same thing to the Tories in 1974) Also, when he stood down as PM in 1955, he was EIGHTY!
Many Tories knew that Labour had an enormous lead in the polls, that's true. But unfortunately, they were not the ones in charge of the party. Macmillan, for instance, was gobsmacked that his bosses didnt seem to realise the danger they were in.
There hadn't been a General Election since 1935. During that time, the Conservative Government had made just about every cock up in the book. Including getting us into a war we were completely unprepared for. I don't see them winning in the mid 40s. Certainly not with those MPs. (Admittedly, Labour would have landed us in the same mess, but they weren't in power)
Churchill may have been personally popular but he played very little part in the day to day running of the government. That's why many historians say he wasn't a particularly good PM, because he was never in control of government policy. It also made people see Attlee as a potential PM, as he was a very good committee man.
"Had Churchill pushed more on the social reform front and got the left out of the BBC and propaganda arms of the government plus this idea of a British Imperial Union he may well have won the election"
The whole point about Churchill as PM is that he didn't have the patience to do any of this. Also, the 'left' at the BBC and the propaganda arms of the government is most of them! You also have to question whether, if the Tories had proposed social reform, the electorate would have entirely trusted them.
Fair point about India. My point should have been that it provided a substantial part of the resources, such as food. It also provides a lot of troops. 2 and a half million Indians fought for Britain in WW2, all of them volunteers (two-thirds of the troops in Burma, for a start). Which then leads to a question of what happens to India, especially since Churchill was extremely dead against their independence. During WW2 he accused Indian troops of being useless and on the point of mutiny (at one of the big conferences)
The other thing is, I just don't see the Dominions giving up ALL their political and economic independence, particularly to a country that is very centralised in the first place. A Federal Union is another matter. But then, how do you run it. In the 1940s, I think they are best off where they are.