Importers contribute to us by lowering the cost of goods.
After the past thirty years, that strikes me as a manifestly false assumption.
The lower costs do not compensate for the lost wages and social decay (higher taxes), which further reduce demand for American made goods and concentrate capital either in the US financial sector or abroad. The drop in demand stemming from the pauperization of Americans further drives consolidation of American businesses who then connive with politicians to extort monopoly rents.
"Free trade" is effectively a death spiral for the United States, destroying both our economy and our political life.