U.S. ports from Maine to Texas could shut down Tuesday if a union representing about 45,000 dockworkers carries through with a threatened strike. A lengthy shutdown could raise prices on goods around the country and potentially cause shortages and price increases at big and small retailers alike as the holiday shopping season — along with a tight presidential election —

A strike by the ILA union at East Coast and Gulf Coast ports puts billions in trade at risk. CNBC's Lori Ann Larocco reports on the key data points underpinning the potential economic fallout.