The title says it all, but I was watching the first episode of BBC's documentaries on the Cold War, and it showed how Clement Attlee replaced Churchill as the British representative midway through Potsdam conference, because Churchill had lost the bid for reelection. How could such a seemingly popular and reverent figure lose that election when you would think his popularity would be at an all time high for preserving the British way of life during the war and ultimately leading them to victory?
I want to take a stab at this because no one else has. I've recently read much of Wm Manchester's bio and have read about WW II most of my life. But am in no way a Churchill scholar to take up my mistakes and omissions. I just thought I could give a starting point to a most interesting personality, and perhaps one of the most crucial leaders of twentieth century.
The short answer is that the real question is how did, a guy like Churchill become PM in the first place? the pt. being that he went about politics in way that was not likely to make him universally liked which is the opposite of many politicians we see today
Churchill was often at the forefront of controversial issues; and being that way does not often pay off in terms of wide spread appeal. Most people who win elections are quick to jump on bandwagons when they see the handwriting on the wall and are careful to avoid anything controversial. Mainly because people will easily recall the dumb things you promoted, but when something good happens everyone will join in so it doesnt really pay to be in the forefront.
CHurchill was associated with the Gallipoli disaster in 1916 which probably wasnt pulled off in the way he would have liked (the amphib invasion being a huge fiasco) but nonetheless he had to take the blame. He was constantly against Mohatma Gahndi and his movement, and at some pt. mainstream political thought moved away from this. He was also famous for being about the last man to support the Duke of Windsor (Edward VII at that pt) before he had to abdicate. Typical of Churchill he probably felt something for him on a personal level and this may have been his motivation in urging people to slow down the abdication crises. But the pols were out for blood and Churchill paid a price; again people thought he was finished.
So he was associated with lots of failures; so much so that even when his party the Conservatives were in power in the late 30s he was not given a high position in government, he was a so called "back bencher" a member of the party in power but not given high office himself.
he thus became basically a critic within his own party. And he became famous as the most vehement editorialist against appeasement. He turned out to be prophetic of course, and given that he had loads of access to much of what was going on in the military (for example: he was aware of radar from its inception; he knew that Poland had been invaded before anyone in Chamberlains cabinet)
So given that he was: a great orator; the prophet who predicted appeasement would lead to war and pretty much a military insider he became the natural choice to lead a coalition government. HIs party still commanded the most number of votes (not a majority) out of three major parties. So the King requested him to form a new goverment when Chamberlain resigned, and I think it was expected to be a coalition of three parties (not sure if the coalition idea emanated from Ed VIII or just the party leadership). He was essentially a critic within his own conservative party, a party that was still in best position to form a government and given his stance he was a natural choice to lead a coalition as he was foremost critic within the most populous party.
So even though he was never wildly popular, he was respected by all three parties for a number of reasons: he was personally loyal (see above DUke of Windsor as well as his support of Chamberlain when that prime minister was cooked); he was very knowledgeable in military stuff, his ability as an orator and a writer of a rally piece was probably the best in England at this pt.
Thus he made a perfect choice for a nation that wasnt looking for a popular leader but one who would take on Hitler head on. ANd he did, he was basically the UK's answer to all that Hitler/Nuremberg rally shit that people had been watching in newsreels for the past decade. He was one guy the Nazis knew would fight them to the death and willingly die if he had to. He was a perfect choice to the wildly flailing fuhrer who talked about living space. This guy Churchill was funny, and serious, and subtle in his wit/wisdom and going to fight to the last bullet. A perfect choice.
WHen the war was over; the people were looking for change. Churchill was not the most progressive guy in the world and there are two other parties Labor and Liberal who were looking to make gains in the new elections. I dont know much about party politics in the 1945 elections so I will leave that to someone else. Here's a quote from an american, Ralph INgersoll observing the UK in 1940:
"Everywhere I went in London people admired [Churchill's] energy, his courage, his singleness of purpose. People said they didn't know what Britain would do without him. He was obviously respected. But no one felt he would be Prime Minister after the war. He was simply the right man in the right job at the right time. The time being the time of a desperate war with Britain's enemies"
Alanbrooke, who kept a diary, said about him. I am paraphrasing: WIthout him, England was dead lost, and with him at the helm England was going from one disaster to the next. There is also a bit of truth in this because Churchill had a lot of odd ideas, such as the Italian campaign, another campaign in the Balkans, etc but he also came up with the Mulberry artificial harbors.
Note also that Churchill changed party a couple of times. He went from conservative to liberal prior to WWI and then he went back to the Conservatives at some pt. in the 20s I guess. I dont know if that was a common thing back then in UK or not, but should be taken into account that this was a guy who was a maverick and followed his own gut about policies, not always with his thumb to the wind of popular opinion.
If I had to compare him to someone you might think of Col. David Hackworth who fought in Vietnam and was longtime critic of both that war as well as US foreign policy in general. Its a character that does not attract universal like, which is what pols thrive on. But it has its advantages in time of war. I cant think of many others.
The most fundamental answer is that he was not up for election. Unlike the US president, prime ministers are not elected. They are invited by the monarch to "form a government", and by convention, the person invited is usually leader of the party which holds a majority in the House of Commons, or leader of a coalition. You have seen this process in action a few days ago, with Theresa May replacing David Cameron with no election being held: the Conservative party held an internal selection process to find a new leader, and as a result she was called to the Palace.
The 1945 election was concerned with the election of individual Members of Parliament, forming a Labour majority, with Attlee being asked to form a government. Attlee was not a "personality politician" in the same way as Churchill - the election was dominated by a preference for Labour policies over those of the Conservative or Liberal parties, rather than for him in particular.