For everyone worried about their Rabbi/priest getting sued:
The same way a Catholic priest can't get sued for not marrying off a Jewish couple (even though Jews are a protected class) a rabbi can't get sued for refusing to marry off a same-sex couple. The state can not dictate to a religious institution how to run a religious ceremony, discrimination doesn't play a role here.
A Catholic priest can't get sued for turning down a Jewish couple, but can he get sued for turning down a Black couple?
LGBT rights groups have framed themselves in the same category as Black oppression. This is the reason bake shops and photographers have been bullied and beaten down for refusing to service gay couples.
While you sound overly confident about pastors not being targeted, it appears that many are worried. Aside from pastors, what about other wedding service providers?