The answer for me is sadly rather simplistic it's not what they stand for it what they don't. Trump doesn't stand for any form of socialism, internationalism, liberalism and take a very introverted look of the outside (of the USA) world. Fostering the idea nationalism and exceptionalism. This done through creating an enemy that doesn't really exist such as Schrödinger's immigrant the one that is both taking your job and costing you money.
The wall is a prime example it's a completely useless vanity project but do you have any worry about Mexican immigrants. Trump's your man whilst the other side won't put up walls they don't think it's an issue. Who cares about the wall he's clearly on your side though.
The 350m on the bus is another example from a UK perspective look past the detail about the false figure and spending it on the NHS. Nobody believed it even Brexit supporters but it conveyed the emotion we spend money on them let's spend it on us. The other people want to give your money to other people that isn't you.
It's emotive of what they don't stand for rather than what they do.