There was to a certain extent an expectation there would be big social change after the war, after WW1, the extreme economic conditions of the thirties, Orwell wrote that England was closer to revolution than ever before.

Of course actual revolution wasn't on the cards, but voting for an arch Conservative like Churchill was never going to happen either.

The 1945 election brought in a radical, left wing Labour government, and what has since been called the post war consensus, the NHS, the welfare state, mass social housing programs, nationalisation of industry etc.

Churchill was reelected years later, once these changes had happened, but there was really no chance of a Conservative winning the 1945 election.