A border tax is a tax increase. The cost will be passed along to consumers, depressing sales in both countries. That means job losses and higher prices.
Border tax = more economical and competitive to manufacture in USA = more items manufactured in USA = more middle class jobs in manufacturing USA = higher wages in a full time job with BENEFITS instead of 2 part time jobs in retail with no benefits and low wages.
99% of workers in manufacturing would gladly pay 20% more with 50% higher wages than in part time jobs.