During the 2016 election, white evangelical Christians voted for Donald Trump en mass. Of course, Donald Trump isn't religious and said he doesn't ask God for forgiveness, which is an essential tenet of Christianity. Even a new Christian understands repentance, but Donald Trump doesn't.
White evangelical Christians dumbed down their standards for a self-absorbed, narcissist, sociopath - their rationale - they wanted a pro-life Supreme Court justice. While they might be happy with Trump's pick, the judge is a corporatist judge, who isn't for the working-class, as this election was supposedly about, so they screwed themselves, but think of themselves as blessed with Trump's pick.
White evangelical Christians claim Donald Trump meets their standards by fulfilling his promises. However, the rest of us understand Donald Trump is a charlatan and a liar. He's done nothing but sow the seeds of resentment, chaos, white supremacy & class-warfare.
What it all comes down to is a worldview that significantly differs from ours. Conservatives, some, vote Republican regardless of the opposing candidate because generally the GOP is against abortion, pro-gun, against gay marriage, and for religious freedom. Keep in mind, the religious freedom they support is their interpretation of their Christian religion, not religious minorities.
So, how do you change a person's mind, who disagrees with everything you stand for - well you can't change their worldview without proof that rightly contradicts they preconceived notions. For example, having a pro-life conservative Democrat might make them reevaluate their thought that only Republicans support their ideology. Those who claim the Constitution is their second-Bible should know the Constitution has things in it they might not like - such as gay marriage, and a woman's right to choose. If you don't want gay marriage, don't get gay married. If you don't fancy abortion, don't have one. Of course, you should live by your principles and values, but that doesn't mean by following your pastor's vote, you're right.
A worldview, in which you believe the end of the world could happen at any time, you don't think about the future because you're concerned only for today with glee for Armageddon - the end of the world.
The problem with white evangelical Christian support for Trump boils down to preserving the white Western culture; it has nothing to do with religion - despite the claim of religious freedom. Donald Trump did an excellent job of pitting Americans against each other and scapegoating. Your problems happen because of mass immigration or blacks or Mexicans taking your jobs. Whatever your problem, it's somebody else's fault, not yours.
With factories closing because of automation and companies shipping jobs overseas to pay workers less - it's not the companies problem. People feed on fear and make decisions based on anger. Thus, we have Donald Trump to preserve the white culture and a theoretical savior for the white working-class.