"Remember, this isn't just some random issue he's talking about. Trump has so far made the China trade issue the basis of his campaign. How often do you see a candidate bring forward an issue otherwise not at the public purview for the purpose of winning votes, only to back down on that? If a candidate is going to bluff on an issue, they're generally going to bluff on an issue that is already generally popular. Debt reduction comes to mind here.
Also, remember that it would pretty much be the worst bluff imaginable. Unlike pretty much every other desired policy, the President can authorize a tariff through executive order, within congressional limits. In 2010, Congress passed a bipartisan bill to authorize the President to increase tariffs against currency manipulators (China included), although I'm not sure how Obama reacted to it. Either way, if Trump is going to bluff on an issue, it sure as hell shouldn't be an issue which he can conduct by executive order. Otherwise, he can't blame the other side or internal politics for preventing reform on that issue. Once again, debt reduction comes to mind here.
In addition, remember that Trump is advocating that stance. Your "he won't do X because it's bad for the country" is EXTREMELY subjective and, quite frankly, egotistical. You are claiming that because you believe X is bad for the country, he must also believe that X is bad for the country.
First of all, you're not a mind reader, so there's no way you can claim to know his thoughts. But second, and more important, your stance assumes that your view is the universally accepted viewpoint of the community. The fact that Trump can, and has, made arguments to the contrary contradicts the fundamental thesis of your argument."
Ok... what you are saying here, kinda of contradicts itself, doens't it? First you say that this reform would not be an effective bluff because it doesn't have popular support. Then you say that, contradictory to my opinion, Trump may have an opinion that differs from mine, and so might others. In order words: the reform does have popular support.
And yes, I think I agree with the latter. There are plenty conservative and plain anti-Chinese Americans who would definitely support such a reform. Especially if Trump is able to get it into the right package, something like "Finally fighting off the commies" or "The stop to Chinese market abuse" or anything like that, that basically exclaims "we are anti-China!". There would definitely be support for such policies.
Why is this a bluff though, and not a reform he truly intends to get through congress? Why, either he truly is an ultra-conservative who has a warped view of the world and still think the USA is overwhelmingly powerful in every aspect and that no other country on Earth can even attempt of dreaming of contesting the USA on anything. Either that or he knows about world politics, he knows about how US influence in South America and in Africa is decreasing due to Chinese investments (for instance, China building roads to connect both oceans in South America to not have to rely on the US-controlled Panama channel), he is not too blind to see the US's power to control the South-East Asian area decreasing due to a more powerful Chinese navy. And needless to say, how careful the USA has gotten nowadays not to upset China is only proof of its leaders recognising the growing Chinese influence. US dependence on cheap, Chinese products and on Chinese rare earth elements, just to give a few examples. Not to mention the US's huge debt to China, etc. etc.
Now if he is able to see all these points, he may know that putting a tax on importing Chinese products will definitely have a negative effect on the US economy. First of all, even though the 25% tax may seem lucrative for the US government, for smaller businesses it may prove fatal as many of the cheap products that they sell in the US, are originally imported from China (Made In China). Furthermore it'll only provoke China, hurting US-Chinese relations. Now this may be on of the aims of some people, but I doubt it'll have a positive outcome. US-Chinese relations aren't that good as it is: hard to cooperate, both countries are easily provoked; but you should not forget that the US is very dependent on China, not only for reasons mentioned above, but also to enforce trade embargos or to even take military action on countries, like Lybia.
The 25% tax will do no good for US-Chinese relations and will only harm the US, and I doubt that this Trump guy doesn't understand it.
But why does he use this policy? Oh i'm sure he uses policies such as lower taxes and "let's fight off Obama's evil Health Care" as well. However, you have to remember that when he starts his own political party, he will have to have policies that aren't being promoted by another party, especially not the party he just defected from. It will only make him uninteresting and he will lose in the long run due to people thinking "This guy has nothing special to offer, might as well vote republican instead of him, no independent has ever won US elections anyways. i'm not gonna waste my vote on someone who has nothing special." This policy, however, is quite special and is therefore sure to attract some conservative votes.
If this isn't a bluff though, if things start to go wrong, then he won't be able to blame it on others, as you stated yourself. That would be political suicide. He'd lose his image and therefore lose support all over the country, which would end up in a loss in his business (you said he was a business-man as well, right?). And if he does put through this policy, and China does not back down, you'll get into a situation as you posted in response to Little Paul.
"Anyway, as for the split to being an Independent, I'm personally more willing to accept that he's bluffing on that one, as he was careful to give himself an out on that ("if I think I can win as an independent"). However, remember that we're not talking about some random senator. We're talking about a businessman with deep connections among both the business and political world and a level of cult personality among voters from his TV show. In addition, the Republican party is an increasingly a divided organization with the rise of its tea party wing, which Trump can capitalize upon, if he so chooses. Remember, the major assets a political party provides are cash flow and legitimate endorsement. Trump has close enough ties with the business world to take care of cash flow, so legitimacy is the only thing they have to offer... which is hindered anyway by the GOP split."
You forget that in the US the political parties also provide politicians a broader public. And independent conservative will only attract conservative votes, close to no liberal votes. However, a Republican conservative will still attract Republican liberal votes (yes they still exist), due to the heavy anti-democratics sentiment.
I also do not think a GOP split is something that will positively affect the parties that emerge out of it, but that is another subject.
And as you said, he already provided himself a way out of his bluff, so I doubt he won't use it.
Maar doodslaan deed hij niet, want tussen droom en daad,
Staan wetten in de weg en praktische bezwaren,
En ook weemoedigheid, die niemand kan verklaren,
En die des avonds komt, wanneer men slapen gaat.