The problem with this type of thinking is connected to stereotyping. It appears that whoever wrote this naturally assumed that immigrant Africans and Muslims would vote against same sex marriage in Ireland. This individual has no way of knowing where these persons stood on the matter and to conclude they they would vote against same sex marriage, without speaking with them, is stereotyping.

Just as not all Xs do Y, it is the same for any group of persons who share some traits/characteristics.

For example, I’m a black female who voted for Barack Obama in 2008 and 2012, but I did not vote for Jesse Jackson in the GA Democratic Primary when he ran for POTUS. For anyone to assume that I voted for Jackson on the basis of race is a huge mistake.