Among people who voted for Ted Cruz in 2016, what reasons did they have for preferring Cruz over other Republican presidential candidates?
Ted Cruz was the choice of many among the Religious Right (Cruz is an evangelical Christian and a leader of a form of Christian nationalism). He is pro-life and opposes equal marriage.
Cruz was also a representative of "Movement Conservatism", a grouping that is in favour of small government, uniformly low taxation, and significant reductions in the welfare state.
In most policies, he is consistent with the more hard-line position in the Republican policy spectrum, and gets support from that wing of the party and the country.