Johnson, Corbyn, Truss, Sunak - all voted in by relatively small numbers of people (e.g. 80k in the case of Truss IIRC), yet they are somehow the leader of the party and potentially even PM.
This is where labour shat the bed I think with Corbyn - totally obvious that he would be terrible as a PM yet the favourite of the popular vote of self-selected labour party, who of course are too extreme to represent the common person on the street.