Sure, the US could massively out produce Russia when it came to nuclear weapons. But the political will really isn't there.
You think that Biden is going to go to Congress and ask for funding to drastically increase the US nuclear arsenal? Or that Congress would give it to him at the moment even if he asked?
He would have to give massive concessions but yeah increasing the arsenal is possible. Problem is the democrats need to get used to the idea their not going to get their way all of the time.