As a a simple example, here in the UK the current Labour leadership is a throw-back to hard-left Labour and UKIP continues to gather support on the right. The c

As a a simple example, here in the UK the current Labour leadership is a throw-back to hard-left Labour and UKIP continues to gather support on the right. The current center-right Tories have enough support to govern and it looks like it will be at least another election cycle before center-left Blairites are in a position to challenge. Like US politics, sometimes changes at the upper levels can simply be the avalanche effect from a few shifts at the edges of the electorate.