I didnt select parties which were wiped out to an extent that they never won again.
OK, how about the British Labour Party in 1931. 287 seats out of 615 in the 1929 general election, when they were the largest party and formed a minority government. A small split over austerity measures during the Great Depression, led PM Ramsay MacDonald to form a National government. The Labour Party was crushed in the 1931 general election, electing 52 seats out of 615 including 6 unendorsed candidates. The party was back in government during the 1940-45 wartime coalition, before winning a large majority in the 1945 general election.
Wiki says Ramsay MacDonald was still PM after that election. And anyway i said "worse" not "worst" as these I felt were similar defeats
Republicans and Tories were in power for over a decade
During their peak (1980s for tories, Coolidge presidency for republicans) they were very popular and their opposition was very divided
Their last term in office they grew more and more unpopular due to the perceived inability to govern the country and deal with their problems
The opposition party united around the candidate who promised change and was a new type of candidate for them and won in a historic landslide for that party
Poll
