And tens of thousands of American jobs will be gone. With less pressure on other stores to compete, prices will rise.
I don't like the fact that we are funding China any more than you do, but we've got to anticipate and compensate for the unintended consequences!
If Chinese goods get banned, Walmart will find another source for the goods. There will be temporary shortages that will hurt retail businesses, and people will likely end up paying more for the goods which will drive up inflation and possibly retard sales because consumers will be able to afford less, but it isn't going to be any worse for Walmart than for other retailers. If anything I would expect that Walmart would do better than their competitors because they have generally shown themselves to adapt to changes in their supply chain more quickly.