I don't think you get it: competing with a government isn't "competing" in the normal sense. Consumer demand? Doesn't matter. If all other cryptos are made illegal, or have higher taxes, or are harassed more by the Trump administration for the sole reason that they don't make Trump money, then whatever consumer investors want isn't going to mean anything.
I don't think you understand the implications of such a government policy. First of all, just because Trump wants cryptos to be banned, doesn't mean US citizens will start unquestionably trading their cryptos for Trump's coin. If Trump's administration puts pressure on the cryptocurrency space, then there will be more outlaws and people migrating elsewhere.
Maybe his coin gets pumped, and he gets a lot of money. A shitcoin is not a competitor, for the same reason USD is not a competitor to Bitcoin.
Sure, there will always be outlaws.
Bitcoin's trillion dollar market cap is based on it being a mainstream
legal investment that is available through simple mainstream apps, brokers, ETFs, and so on. If it were to become a black-market thing, 99% of investors would leave it, and so would 99% of Bitcoin's market cap. Most people don't want to break the law and risk prosecution--especially when there's a perfectly legal alternative that gets them the same thing (because most people just buy Bitcoin to speculate).
Nobody is imagining Trump could "kill" Bitcoin in the sense of removing it from existence, but he could very easily erase almost all of it's market value.
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I have been talking about the threat to Bitcoin itself here, but I think another very significant threat is to others in the broader crypto space. Trump will surely want the profits of companies like Binance, Coinbase, all of the miners, and so on.
Ever heard of "Made In America"? That's an extremely strong political slogan here. It's the very heart of Trump's political message (even though his protectionist policies actually weakens America's ability to compete, but whatever).
Imagine the Republicans--including all of their media, all of their surrogates like Elon Musk etc., all of their talk-radio and podcasters--all saying that people should by "American crypto" not that unpatriotic foreign stuff.
The Bitcoin community has been playing a very, very dangerous game by entering into the realm of politics...