>Back in 1917 Switzerland used to use majority system in the parliamentary elections. This led to a situation where the Liberal Democrats got only 40.8% of the vote, but 54.5% of the seats in parliament. The absolute majority allowed them to pass the laws, regardless of the will of the 59.2% who voted for other parties.

>Needless to say, Liberal Democrats torpedoed every attempt to replace the majority voting system by a proportional one. If the instrument of popular initiatives was not available, it would be a dead end. The voters would have to wait until Liberal Democrats lose some of their voter support. But even then, thanks to the majority system, an absolute majority in parliament could be won by another party, who would again find it difficult to abolish the system that brought it to power.

>General dissatisfaction with the state of affairs led to the launch of the popular initiative "For a proportional system of elections to the National Council" in 1918 which succeeded with 66.8% votes in favor.

>In 1919, elections were finally held using the new, proportional system and Liberal Democrats lost the absolute majority.

My theory is that the success of radical political change (peaceful or revolutionary) decreases with population size. The population of Switzerland was around 3 million in the late 1910s. The population of America was less than 3 million during the entirety of its revolutionary war.