The F150 lightning, as I understood it, was being discontinued because of poor sales. And that wasn't because of foreign rivals (nobody else wants or makes these large trucks, except for the US market), or domestic competitors - let's face it, the Cybertruck wasn't going to give any truck a run for it's money and while the Rivian R1 is good, Rivian are a start-up not equipped to take on Ford.
The reason America buys foreign cars is quite simply because it has, for many decades, consumed far more than they could ever make, affordable workforce or not. Trump's protectionism is more like living in denial. Demand is simply too high for any domestic supply to meet. Even Ford's domestically made vehicles are more than 50% foreign parts.
US Unions objecting to automation and at the same time demanding higher wages just makes it cheaper to produce elsewhere. It all boils down to if the American consumer is patriotic enough to want to pay extra for that "made in the USA" sticker. And past history suggests not.