It depends on whether you believe US action is overdetermined, but I think if Trump didn’t get elected we would have continued on the path of free trade. His election wasn’t predestined. He had just the right mix of features to win at the time, but if this basket of features didn’t exist it’s not hard to imagine the country going down a very different path.
Biden wasn't a free trader at all, more alike to Trump in trade than many would like to admit.
If we had continued on the path of free trade without "dealing in" those displaced by free trade, the pressure would have continued to grow. It certainly could have exploded in a different direction, at a different time, with a different champion, but so long as it was repressed instead of addressed it was always destined to explode.