Which country should I apply to for my Schengen visa? [duplicate]

Yes, it looks very bad and it seems you might be misjudging the risks. If your citizenship is somehow an issue, showing up in Germany with a Spanish visa and no coherent explanation for your first Schengen trip would be a huge red flag, much more likely to lead to problems than a straightforward application to a German consulate in the US.

If you disclose your intentions in your application, Spain should decline to process your application, send your documents back, refund the fee and invite you to apply to Germany. That's not too bad but you would just be wasting your time.

But if you don't disclose your real intentions and pretend you want to go to Spain and are found out, that's fraud and an actual guaranteed refusal. If you do manage to pull it off and show up at the border, you could still be found out, in which case your visa would be annulled on the spot and you would be sent back to the US by the next flight. This would make it nearly impossible to get another Schengen visa, from any country, in the near future.

I believe you are doing the German consular staff an injustice if your think there would be a "guaranteed rejection" based on your citizenship. Sure, people from some countries are under increased scrutiny due to past problems with their fellow countrymen, but that is not the same. Each application is examined.

It looks bad if you apply at the wrong country. It could be a mere clerical error, e.g. asking for a German Schengen visa if you merely enter the Schengen zone in Frankfurt and transit elsewhere. In that case you will be informed where your application should be handled, but they will note that you obviously didn't read and understand the instructions.

Deliberate lies about your itinerary can be a problem before, during, or after the trip. If they catch you at it, that will be entered in the Schengen database.

There might be one way around it. Ask for a multiple-entry Schengen visa with the first trip e.g. to Spain. Make no firm plans yet for any subsequent trips. Make the first to Spain trip exactly as declared. But getting a multiple-entry visa from Spain might be more difficult than getting a single-entry visa from Germany ...