A really good answer already has been given by wanderer. I think one of the problems is "oversimplification " what is in a definition.
For one “left to right” is incredibly broad. Someone can be for a great environment (is that left?) and say for lower taxes(is that right?). I think most people are somewhat on both sides of the spectrum and when something works it works.
As for definitions, “Socialists” are used by tons of regimes and the party NSDAP name stood for Nationalist Socialist Deutsche (=German) Arbeiter (=Labour) Party. I think only the last word of this is uncontested.
It is utterly ridiculous that any other “Labour party” is comparable to the NSDAP because it has “Labour in the title”.
Actually a lot of “Socialist” parties used wording like “Labour Party” UK/NL or Social Democrats (Netherlands earlier).
Sadly we did and do live in a World were people are labelled “sheeple”/fascist etc etc etc for nothing coming up with these names just served the purpose of attacking the other side. IRL I would say, can you define what according to you is a list of things “Socialists is and do”. A sort of working definition. If he has 10 things that constitute that decision you can point out that it doesn’t match whatever the Socialists you support do and think.
The latter works in IRL and a cup of coffee not in Twitterland were people go as extreme as possible. IRL mostly when I discuss with people with other views we seem to at least understand were the other is coming from and often agree that on “our side” there are some minuspoints as well. If this makes sense!
Good luck discussing and great question.