In this case, the ideology at play is "Muslims are evil and we must keep them out", at least it seems to be for a lot of right wing posters. Motor vehicles are more essential in normal life to most people than guns are. If you're a farmer or a hunter or somebody shooting at a controlled range then guns are fine but most people should not need them in everyday life unless they are police officers or security forces. The unnecessary profusion of guns in the US guarantees carnage.