More or less, yes. Though white nationalism is really a post-war ideology. Some, including Jefferson, were probably too, shall we say, *accomodating* to Indians than some modern white nationalists would like. It'd probably be more accurate to say they were white supremacists - but maybe even that is wrong as it was pre-Jim Crow. Another significant difference is that the Founders lacked the virulent Jew hatred. But yeah, even as late as 1958 only 4% of Americans agreed with interracial marriage between blacks and whites. I highly doubt even a relative left-winger like Thomas Paine would have favored that. On the other hand I think New York refused to adopt an anti-miscegenation law even with significant numbers of blacks there. Can't remember exactly why at the moment but my impression is that it wasn't good.