As the 1906 UK general election results rolled in, it became clear that the Conservative party, after 11 years in power, had suffered one of the most disastrous defeats in its history. Of 402 Conservative MPs, 251 lost their seats, including their candidate for prime minister, defeated on a 22.5% swing against him in the constituency he had held for two decades. Rising food prices, unpopular taxes and an opposition that promised to spend heavily on an expanded welfare state all contributed to the Tory downfall that year. But something else had tipped the opposition Liberal landslide over the edge – compulsory vaccination.