The thing you have to understand about British politics is that the Conservative Party is rather good at it. In the last 100 years, the Tories have been in government in one way or another (majority, minority, coalition, national) for roughly two-thirds of the period.
Such was its dominance of the 20th century that when he stood down in 2001, William Hague became the first Conservative leader not to become Prime Minister since Austen Chamberlain in the 1920s. Labour, on the other hand, has produced two election winners since 1964.
