Street power

THOUSANDS of demonstrators trying to topple Hong Kong's legal ruler C Y Leung and set terms for the 2017 election symbolise a new political trend: Whichever constitutional way a ruler has been brought to power, the ability to continue might depend on the consent of the social media-connected populace forcing its will onto the streets. That at least has been the case with Mohamed Morsi of Egypt and Ukraine's Viktor Yanukovych. Mr Leung is untainted by corruption. Yet, even if he continues, his effectiveness has been badly compromised.

In the past two years, a political trend has emerged that takes legitimacy of government into perilous and…