United States government has always been against using bitcoin. What is the reason?
They say bitcoin is used for illegal transactions. What do they mean by illegal transaction? Do you think they mean buying and selling drugs?
I disagree that US is always against Bitcoin, the wrong picture was created when they react on Libra, and by saying some thing about this project they also need to mention Bitcoin as most powerful cryptocurrency.
Maybe you're referring to recently statement given by
Brad Sherman, US Congressman who is saying that Libra will be "tool for drug dealers" and that cryptocurrency should be prohibited as it only serve for illegal activities. Even though President Trump himself says something similar, I doubt they can stop cryptocurrency to continue to thrive and conquer more and more markets.
You should know that the US has the highest number of crypto ATMs in world, and that Coinbase is US company - so crypto is very strong in that country. US is just want to keep US dollar as main reserve currency, and they been losing in that field for some time. Anything what constitutes a threat to that goal including Bitcoin is susceptible to attack, and this also include China&Russia which are an obvious example how sanctions and trade war can be used to achieve their own goals.
Drug is something that is just a threat on paper, you can buy it same as firearm at every corner, and it is almost like a constitutional right in US.
Even without Bitcoin countries have been moving (albeit slowly) to lower the USD dominance as "reserve" currency. This is not something the US can force others to do or not do, but they can pressure (especially with the likes of Trump) still things like the € exist to counter that.
Now that Bitcoin exists, this adds to the pool of coins countries can go to for reserves. Its optional, no one is forcing anybody to hold neither USD nor bitcoins, or Gold for that matter.
In general Trump is correct, but at the same time powerless. Yes the US is losing supremacy in various fields, but no his action do nothing to revert it, just annoy his own voters, but whatever the Americans should know whom to vote for better... Take for example China, he is waging a little war with them, but there is zero chance China will bend to his will. Trump never ever faced someone like the State of China, his business experience is simply inadequate and will prove in failure. China really doesn't care what Trump ever does, they'll laugh if trade stops entirely, as they have the rest of the world to trade with, while America, loses its cheap source of manufactured goods, that Trump cannot simply restart production inside America, because Americans aren't going to work at the low wages the Chinese do, and the few that would be willing to do it, are precisely the immigrants he wants out, so no.