It's pin-everything-on-China season
it works. Recently it worked in the Soviet Union (siege mentality) and works great in Russia, worked with war on terror (them evildoers attacking our American way of life), worked with Brexit (our European "friends" with their bent bananas) and works great in those European states where it fits politicians to find an external enemy to blame (rightly or wrongly), be it refugees, the whole of the EU, or just your over the border neighbour. Why should it not work with the US, to deflect blame from their incompetent president (great, great president, best in their history, etc.). Blame somebody else, and China is a great scapegoat, first they took away American jobs and now, hints our great, great president, they also, cause thousands of deaths of innocent, hard-working Americans.
People, in general, are stupid (and / or lazy), and they buy this shit because they want SIMPLE. Simple EVERYTHING. So politician give it to them. Level of sophistication required: zero. Level provided: zero. What you want is what you get.