I think you have the wrong end of the stick (trying to map it onto contemporary politics?).

Caesar was killed by the same people (hardline conservative ultra-wealthy 'Optimate' families/factions) who also brutally murdered the tribune of the plebs (person appointed to beg the ultra-wealthy for favorable legislation) and his supporters not once but twice. He was killed for the same reason too - land redistribution, limits on slave labor. That was called 'tyranny' by the elites.

Crassus was wealthy before Caesar and died before Caesar took power. This kind of politicking was just a necessary evil in the Roman Republic - which always was an oligarch-controlled plutocracy and never a true democracy as we know it today (e.g. Athens). It was 'pay to play', sponsorship of the ultra-wealthy was not optional.