I’ve seen other comics where Everett rejected the concept. One was when he told a woman he believed in it (in the sense of wanting it to happen) and threatened to kill children, and another when he told a man who brought it up that he was introducing him to race homicide. (I guess the term “genocide” hadn’t entered the vocabulary.)

Well, according to that Wikipedia page, people who used the term “race suicide” believed that “desirable” people were having too few kids and “undesirable” people were having too many kids.

So Interpretation A of this cartoon is the following:

1. the Landlord believes in the “race suicide” concept, and believes that Everett is an “undesirable” person who has too many kids. The Landlord is insincere when he says that Everett is “estimable” and a “desirable tenant”.
2. Everett scorns the “race suicide” concept, and argues for his kids’ right to exist.

And Interpretation B is:

1. the Landlord sincerely thinks Everett is “estimable” and a “desirable” tenant, but just doesn’t want his kids to live there for some reason
2. Everett believes in the “race suicide” concept, and is telling the Landlord that without his kids, “race suicide” would occur.

I’m leaning slightly towards Interpretation A because I think the Landlord is being insincere, but I could be convinced otherwise.

Edit: on second thought, I don’t think Interpretation B Point 1 relies on the Landlord believing Everett is “estimable” and a “desirable” tenant, only on the undesireability of the kids living there.

I mean, he’s punching a guy he thinks believes that, not espousing the belief