Protectionism (in this form) has never been a good policy, but it's always quite appealing to the protected companies - and when companies have the ability to sway elections (money in politics) then you can reasonably expect quite a lot of it to be going on.

  >> works against the interests of the United States though

That's just, like, your opinion, man, especially after the trade deal with China is finalized. About time someone actually raised a stink about what's going on with China and Europe in terms of foreign trade. It's unpleasant work, but it has to be done, moreso with China than with the EU.

FTA: "“Our ultimate goal is to reach an agreement with the E.U. to end all W.T.O.-inconsistent subsidies to large civil aircraft,” Mr. Lighthizer said."

As a US citizen I don't see anything controversial about this stance.

  >> It seems to me that China just gave him some window-dressing 

This form of cognitive dissonance is called "mind reading". You should look it up, unless you're a member of the negotiation team and have direct knowledge of the negotiations.

Your tax dollars are going to prop up a failing company that is producing substandard products that have gotten people killed - I don't see how you could mentally position yourself to be alright with this.

The general idea of protectionism is less controversial - I think it is generally bad[1] due to the economic effects of it. But if you're in favor of protectionism you can check any claim you have to free-market economics or de-regulation for growth at the door, protectionism is basically the Ur-form of regulatory capture and state-capitalism so being pro-Boeing subsidies and then claiming that the US becoming "socialist" is terrible is just logically inconsistent.

[1] I'd leave the notable exception of when it's used to specifically stimulate economic sector growth - propping up a robotics company in TN to create a labour pool that enables other companies to grow out of the labour availability is a pretty good usage.

  >> Your tax dollars are going to prop up a failing company

Didn't read any further. Boeing is not a "failing company".