This is a further twist of a stupid US policy.
Solar panel manufacturers cried foul while China simply out-managed the US players on the supply chain, so the US slapped tariffs on Chinese finished panels. China says, ok, so that's how you want it, and then they slap tariffs on cheap US-manufactured polysilicon. Most Americans (and sadly, most American politicians) don't know that up until recently those cheap Chinese solar panels started life as gravel, coal, and wood chips in America's rust belt. And jobs. Well, not anymore. South Korea, not near as foolish as the Obama administration, and not subject to the same high retaliatory tariffs, is now taking over the lead position in polysilicon. They didn't even say thanks.
Let's tour a polysilicon plant near Moses Lake, WA. Whoops. Closed down a few years ago when they couldn't compete with other countries for China's voracious polysilicon appetite. Hemlock Semiconductor, once the largest polysilicon manufacturer in the world, is hemorrhaging jobs left and right in Michigan. Both Hemlock and Wacker announced huge new polysilicon plants in Tennessee, investing billions, then mothballing them before they hit production because Uncle Sam suckerpunched the US polysilicon industry by playing anticompetitive with the US solar panel industry.
This made sense to an extent when the Democrats were in charge, because US solar panel factories were in blue voting areas and US polysilicon factories and suppliers were in red voting areas. Now it's simple pandering and incompetence.
Be careful with labeling it "American manufacturing". We've lost our worldwide leadership position and while we may buy American more at home, the rest of the world is moving on without our dominance.