They are a fairly small group compared to other marginalized groups, and particularly vulnerable compared to others. There is already a lot of misinformation about them. Average people often dont run into them or understand them Well enough to make informed decisions. Its easy for billionaires and republicans to wield religion against them. They are often vocal about their beliefs. Intersectionality is also important (e.g. supporting and protecting other minority demographics' rights because it is the right thing to do, and tearing each other down is counterproductive) to them, which isnt always the case. Disappearing them sets an example and is a test run for setting up the infrastructure and means to take control. See: nazi germany with the deaf, and current marginalization by the trump administration of the trans and disabled communities.