I don't know about that, or of Trump having claimed to be a good man. However, he does appear to be trying to be a good president and keep his promises. As long as he keeps striving to do the right thing in the name of God, it would be wrong to not support him, as was said in the OP.
Human trafficking (making merchandise of people) is mentioned at least twice in The Law, and probably in more places - for example:
Deuteronomy
21:10 When thou goest forth to war against thine enemies, and the "I AM" thy God hath delivered them into thine hands, and thou hast taken them captive,
21:11 And seest among the captives a beautiful woman, and hast a desire unto her, that thou wouldest have her to thy wife;
21:12 Then thou shalt bring her home to thine house; and she shall shave her head, and pare her nails;
21:13 And she shall put the clothing of her captivity from off her, and shall remain in thine house, and bewail her father and her mother a full month: and after that thou shalt go in unto her, and be her husband, and she shall be thy wife.
21:14 And it shall be, if thou have no delight in her, then thou shalt let her go where she will; but thou shalt not sell her at all for money, thou shalt not make merchandise of her, because thou hast humbled her.
24:7 If a man be found stealing any of his brethren of the children of Israel, and maketh merchandise of him, or selleth him; then that thief shall die; and thou shalt put evil away from among you.
So, as we can see from how God feels about it, it is a serious crime.
Trump is making it his mission now to abolish human trafficking. Perhaps to some, like you said above, they see it as just being rhetoric. However, I personally don't see how you can call it rhetoric when the words are being backed up by actions leading to actual results - see post #8.
I don't know what Trump did in his past and what he may or may not have been guilty of. God knows everything about every person and each person's record of deeds is with Him. People who want to focus on alleged past actions of his are spending their time and thoughts focusing on the past, not on the present. Perhaps, they are so caught up by the mainstream narratives that they may not realize how much is actually at stake for America and the world. Can you imagine what it would have been like, if the alternative had actually won, and become the president? Can you imagine that? What would that have been like? If she had won, we would most likely already be in or even post WW3 (and on the losing side of it) right now.
So, you asked, how do I square what he did with this proclamation to abolish human trafficking, to the things you mentioned that are alleged about the past. Well, basically I don't try to square it. Because God does that, with absolutely everyone, and as He Justly decides it. And with that in mind, He (God) allowed Trump to become the president of the USA, as far as we could see, literally against all the odds.
Therefore, at this moment, I believe it is irrelevant what he may or may not have done in the past (and which we do not know), because what is important now is that he is the president now, so what matters now is what is he trying to achieve now. It's not about him, it's about what is happening with the country and what Trump may be able to do.
And he appears to be trying to do the right, now. To not support a president, that not only has shown he is willing to stand up against the status quo, and trying to actually do the right thing, and praying for him that he might be helped and guided towards that aim, would be wrong.
I believe it is important to focus on what is happening now, not what may or may not have happened in the past. God has a complete record of everything that everyone of us has ever done and He is Judge.
Ezekiel
18:20 The soul that sinneth, it shall DIE. The son shall not bear the inequity of the father, neither shall the father bear the inequity of the son: the righteousness of the righteous shall be upon him, and the wickedness of the wicked shall be upon him.
18:21 But if the wicked will turn from all his sins that he hath committed, and keep all My Statutes, and do that which is lawful and right, he shall surely live, he shall not die.
18:22 All his transgressions that he hath committed, they shall not be mentioned unto him: in his righteousness that he hath done he shall live.
18:23 Have I any pleasure at all that the wicked should die? saith the Lord "I AM": [and] not that he should return from his ways, and live?
18:24 But when the righteous turneth away from his righteousness, and committeth inequity, [and] doeth according to all the abominations that the wicked [man] doeth, shall he live? All his righteousness that he hath done shall not be mentioned: in his trespass that he hath trespassed, and in his sin that he hath sinned, in them shall he die.
33:14 Again, when I say unto the wicked, Thou shalt surely die; if he turn from his sin, and do that which is Lawful and right;
33:15 [If] the wicked restore the pledge, give again that he had robbed, walk in the Statutes of Life, without committing inequity; he shall surely live, he shall not die.
33:16 None of his sins that he hath committed shall be mentioned unto him: he hath done that which is Lawful and right; he shall surely live.
33:17 Yet the children of thy people say, The Way of the "I AM" is not equal: but as for them, their way is not equal.