One long-held truism of American politics held that no woman, no black and no Jew needs to try to run for president of the United States. Given the country's inherent conservatism, any such candidate would fail.
Since the election of Barack Obama in 2008, that truism no longer applies in full. And, in 2016, Hillary Clinton got close, even winning a popular majority, though not the White House.
In 2020, we may reach the point when the third of those presumed barriers will fall — but not because of Bernie Sanders, the oddball leftie candidate.