This is exactly what I'm talking about. I don't know what the lineage of JRJ was, but his grandfather was a Sri Lankan, and his father was too. That 5 generations of proven residency. So, generally, they are regarding Singhalese, and the religion may change with the generation, as some of the elites had. But still, Singhalese don't accept JR as their own.
Talking about Kadirgamar, who was a greatest politician and true Sri Lankan, he was never a candidate for state leadership. Once, President Chandrika attempted to make him the Prime Minister, but it was taken back as a result of the protests of her supporters and religious leaders. After that, Kadirgamar was assassinated. I still remember some news articles that openly mocked that great leader. Once, Prof. Nalin Silva openly harassed Kadirgamar by saying that he was trying to change Buddhist history because Kadirgamar planted a Bodhi tree at Anuradhapura.