The situation is more like the US electing a black president than South Africa doing the same; the Israeli population in 1948 is ~15% Arab, not >70%. Even if we include the Palestinians, the population breakdown is about 2 million Jews to less than a million Arabs (there are now more Palestinians than Jewish Israelis, but that's because of birth rates, which are significantly higher for the Palestinians). That's still a strong Jewish majority, who largely view the Palestinians as being less educated and cultured.