Say whatever will get the conservative people angry.
For decades stirring up fear and hatred for gay and lesbian people was a sure vote winner for the right wing.
Once gay marriage and relationships became acceptable (relatively, I am not dismissing the hardships LGB people still face) in much of the west, they needed a new group to focus that hate to rile up their supporters and suddenly all the hateful shit was shifted to trans people.
Most that spout this hatred to get elected, do not believe it.