Why did the Liberal Democrats collapse?

[Filuwaúrdjan]

All of the above really in whatever combination. Plus their senior figures made the critical error of looking smug. If we're looking at what turned a severe drop in support into outright collapse then that might even be the main thing. Voters are not always terribly rational and if you present a face that seems to almost beg for a metaphorical punch they seem to be more likely to deliver it.