>>/44513/
Marxism-Leninism is a fringe belief and drives away voters in the average democracy. Castillo could've had a much less narrow margin if he had ditched his far left label. For his party to cling on to it despite this, it must have a strong internal faction opposed to a change in label.
Then the campaign promises themselves are already part of the label, rather than a guarantee that actual governance will be as described. Regional precedent is that a very left-wing turn is an option, and this might be more likely for a party already embracing a far left self-description.