I think the phrase 'code words' is being misinterpreted. It should really include the use of collocates. You have all played that game where you complete a well known phrase or saying.
So if I say, for instance, 'GAS' you might complete it with 'STATION' or 'PUMP' or 'BAG' etc. Now, when we read and particularly when we listen we are pre-guessing the next word or words. So if I say, in a speech '.....gas..' you will preguess one of those words I have listed. You think of 'PUMP' with a secondary guess of 'PRICES'. I say Gas pump prices' and you immediately identify with me because we are 'the same'. Now no one will ever complain that the price of petrol is too low! In my next speech I might simply say, '...now look at gas....' and you complete it as above. But I can honestly say that I didn't talk about the rising cost of petrol, nor that it was the fault of corporate greed, but because 'we are the same' you know.
The same applies to our prejudices to the extent that the pronoun 'THEY' can indicate a racist attitude and no intent whatsover to turn 'THEY' into 'US'.
Politicians' speech writers know this (many politicians are too dumb to ask why) but most of the electorate is oblivious and occasionally, just occasionally might ask themselves, 'Why do I think that?'
The answer is simple and it applies to all parties and all faiths:
I think that because someone has TOLD ME TO THINK THAT!
If you want to fight for freedoms in America fight first for FREE WILL.
Many millions and possibly billions or more have been spent trying to create subliminal messaging. On the average human level it goes completely unnoticed but the message remains. I had heard about the popcorn and candy subliminals in theaters for years but the one that stuck out most clearly was when Ronald Reagan announced his run for the Presidency in Philadelphia, Mississippi. Although I would never accept or even consider that RR was a racist, that particular site for his announcement was red meat for the southern white voters that considered themselves "conservative" or Republican. Even in 1980 I had no idea what either of those words meant anymore. They sure as hell didn't mean what they meant during the Eisenhower Presidency.
Thinking back now and considering the landslide victory of RR in 1980 he certainly didn't need to lower himself to that level to attract a few racist votes from the south. Although I continue to like RR for many reasons I could never respect him again for that single action. So much for subliminal messaging.