This is both highly unlikely, and also not actually a problem for Bitcoin! First, it is highly unlikely that the United States will ban Bitcoin, since over the past year major financial institutions have taken huge positions in Bitcoin. With companies like Goldman Sachs, Fidelity, MassMutual, Microstrategy, and Tesla making hundred-million or billion dollar purchases of Bitcoin, the amount of political pressure from the financial world to keep Bitcoin legal will be tremendous.
Second, where national governments have tried to ban Bitcoin, that ban has backfired. Nigeria recently stated that Bitcoin was a danger to their local currency (the Naira), and moved to ban it. Since that ban, there has been a [massive increase in person-to-person trading of Bitcoin], actually accelerating adoption of Bitcoin by regular Nigerians.
What the US Government could do is try to confiscate Bitcoin. This would likely look like what the Government did on April 3rd, 1933, under [Executive Order 6102]. With Order 6102, the Government attempted to confiscate all “gold coin, gold bullion, and gold certificates within the continental United States.” The net effect was that all gold held in banks and other institutions became the property of the Government, replaced with Federal Reserve Notes (ie: debt). This is why it is so important to actually take personal possession of your Bitcoin! The common refrain here is “not your keys, not your crypto!”
Bitcoin was designed from the beginning to be able to survive a ban. As open-source cryptography, the entire thing is basically speech. Also, it is designed to function even under extreme authoritarian conditions such as in China and Venezuela. About the only way to totally destroy Bitcoin would be to shut down all computers, everywhere, and in that scenario, humanity likely has bigger problems!