How can the left not link immigration with the reserve army of labor?
The right thinks that limiting immigration removes the surplus. The left knows that there will always be a surplus but they attack the right on refusing immigration instead of first explaining the reason for the surplus.
Because we've already explained to them that the king has the overwhelming majority of surplus and they're pretending to be too stupid to understand, as an attempt at plausible deniability for racist motives.
You told them or you explained and developed a plan? This is all hypothetical, because immigration also creates jobs, but to somebody threatened with losing their job, it doesn't help that they know that the king is to be blamed.
My assumption is that they believe that a unified society can change the decisions of the king. How do you convince them that the immigrants are on their side?
BTW, it doesn't matter that the king has the majority of surplus. The problem is that he doesn't use it to employ everybody.
The creation of jobs is just the tip of the iceberg; fascists are completely delusional. These aren't smart people who were reasoned into their position. The only way to change their minds is to redirect the social pressure that brought them there.
Of course, changing the mind of a non-dillusional person is already hard enough.
The creation of jobs is everything. If your life stops being a competition for survival, people outside your social ingroup stop being existential threats.