Tim Scott and Nikki Haley, if you must, are both minorities. One is Asian Indian, a woman, the daughter of Sikhs and is accused of adultery (a crime punishable by stoning in some parts--being accused, that is). The other, a black man, beat the son of one of South Carolina's most infamous (segregationist) politicians, Strom Thurmond.
So, why (did they win)? The obvious answer is that they are both solid conservatives, and evince an overwhelming air of honesty and trustworthiness. But it's difficult to overlook their respective races/gender as a factor. It's not the same principle as affirmative action, mind you: unqualified candidates are not considered. One must be conservative to win the conservative vote. One must be a compelling candidate. It's not race alone, nor is it race that is the most important factor.
But it is a factor. It is not a top-down orchestration of reverse-racist policies; instead, these are enthusiasm candidates, who won by the efforts of the grassroots and through intense hype. A not insignificant part of that enthusiasm was their identity. In some ways, it's almost defensive. In others, it's a compelling path to meaningful political victory.