To qualify as "slander" the statement must be false. Characterizing someone who thinks gays are "sissies," transgendered are "off shoots" and would be unhappy about his daughter marrying outside her race as a bigot is an accurate and defensible statement.
https://www.merriam-webster.com/dictionary/bigot
Quote:
Essential Meaning of bigot
disapproving : a person who strongly and unfairly dislikes other people, ideas, etc. : a bigoted person
especially : a person who hates or refuses to accept the members of a particular group (such as a racial or religious group)