The degree to which Trump seems an unlikely Evangelical standard bearer has been widely explored. See for example, Sarah Posner and Christopher Stroop for insightful analyses. Certainly the alt right and authoritarian threads are important. So is the argument that some aspects of the Trump agenda/persona are merely tolerated by evangelicals because they care more about fighting abortion/LGBTQ rights and “preserving” their privilege in the name of religious freedom.
But the support for tax cuts, over assistance for those in need, is not just a gift from Trump to his rich friends, tolerated by evangelicals because they care more about other issue. These budget cuts are in keeping with the religious right’s understanding of a Biblical worldview, and have long been at the very core of its agenda.