If this strip works humor-wise, then most of what makes it work is this guy’s smug expression of smiling confidence, with a hint of pain. That, and the fact that he looks a lot like Jack Palance.
I do not know why the artist did not draw the rest of his hat. The 1940s look of him just made the use of “brother” feel natural.
If this joke has value as a political allegory, that does not make it a political joke. My political enemies are the enemies of logic, wherever they may stand.