Why did the Liberal Democrats collapse?

[Vosem]

Liberal Democrats had strong support from younger voters in Britain, and one of their key platform planks was, and had been for decades, opposition to university tuition hikes. As soon as they got into government, they immediately agreed to vote for Conservative legislation that hiked university tuition, pissing off not just younger voters but essentially their whole base. They have yet to recover from this, though making Tim Farron (who voted against the 2010 hike and loudly opposed the LibDem about-face) the leader is a decent start towards rebuilding.