Fptp is vulnerable to communism

Fptp is only better than pr at stopping communism if it can prevent a majority of voters getting what they want. Communism results under pr if more than half of the electorate vote for it... but fptp would be no better obstacle since if this can be achieved under pr then it will equally be achieved under fptp. In fact it is easier to achieve under fptp because absolute power is possible with very much less than a majority of the vote. Pr is power-sharing fptp gives power to the least small party. Fptp is no more effective at preventing communism than pr and it can be shown that it is significantly worse.