Why are conservatives and liberals so viciously attacking TED CRUZ?

The conservatives aren't attacking him. Its the RINOs: the stereotypical rich, old, country club liberal Republicans from the northeast and who have a great deal of influence in the DC beltway. They see themselves as something of an aristocracy and don't like upstarts or those who would upset the applecart.

The liberal Democrats? They hate Ted Cruz for two reasons. One, they hate anyone who disagrees with them. Second, and more importantly, they see him as a major threat to their future stranglehold on the Hispanic vote; note that they also viciously attack conservative women for similar reasons (fear of losing a majority of female voters).