Liberals, especially the far-left, have a lot intellectually, emotionally, and spiritually invested in their ideology. Their ideology and ’cause’ is an extension of their existence, ‘being’, and purpose. When the ‘right’ loses, for their supporters it’s back ‘work’ or whatever they were doing before. A loss is only a setback, not an emotional devastation. For the ‘right’, there is far less emotional attachment, because their ideology occupies a far smaller piece of their life.
Second, the left generally believes in the Marxian dialectic, that society is shaped by politics and economics (the eternal struggle between the worker vs. the capitalist); the ‘right’, on the other hand, believe society is shaped by a ‘shared national identity’ such as culture, ethnicity, language, or religion. Communities united by ‘shared identities’ provide cohesion and meaningfulness for the right, that is missing for the left. When the left loses, they have nothing to fall back on, because they are in a constant state in decoherence. The left outsources their identity to the ‘state’, so when the wrong party wins, it’s an existential crisis of sorts. Communities and shared identities, however, are much stronger.