> He is not clay, of course, but his policies and ideas can be softened.

What makes you say this? I don't agree and I've seen no sign of it, from mid-2015 until now. Has anyone softened them?

There are two options:

A) Advise him: There's a tiny chance you'll affect his policies, but there's a certainty that you will empower him by giving him your credibility. On a selfish level, he will devour that credibility, because he can only discredit you in return.

B) Oppose him: Your advice and resources will help the opposition slow or stop Trump, and you will give them credibility (which will enhance your own credibility).

I strongly believe B will accomplish far more good than A.

I know it's counterfactual history... but what if his only advisers would have been fanatics? Seeing his rhetoric in the campaign, with a full radicalized Trump, I guess the ban would have been much larger, including many other countries (Saudi Arabia, UAE, Lebanon, etc).

And the same could be applied to other issues: e.g. exit NAFTA altogether overnight instead of renegotiating.

And the only reason why the ban doesn't encompass those countries (Saudi Arabia, UAE, etc.) is because Trump has business dealings there.

Is the argument really that 'it could be worse'? I guess that argument theoretically can be used anywhere, but then what does it mean? Arguably, it's never been worse.

My strong belief is that lack of opposition makes things much worse than lack of advice.

As a side note, one radical advisor people are forgetting about in this discussion is National Security Advisor Michael Flynn.

The argument is that giving up and leaving, is the best way to have a more radicalized group leading the country, and that will result in even worse policies.

You don't want to have a POTUS with majority control of the Congress and a friendly SCOTUS, to be fully radicalized. But that is what you'll get if their only advisers left are the ones wanting him to rule like that.