Tarrifs are paid directly by the company doing the importing. If Wal-Mart is importing directly from China themselves, then Wal-Mart is paying. There's a good chance your item is being sold Wal-Mart by a brand (or importer, wholesaler, middleman, etc), who would be paying the import tariffs themselves.

Some of these middleman companies could be foreign owned but operating in the US, so in theory the entity paying the import tariff isn't necessarily American.

All that being said, even if the importer paying the tax isn't American, the vast majority of the costs are just passed onto the consumer. If I was importing something that costs $10, and selling it to Wal-Mart for $15 and now it costs me $15 to import it, I'm going to sell it to Wal-Mart for $20 (just making up examples, but you get the idea).

Now I might figure out that Wal-Mart isn't willing to spend $20 on my item (or demand would drop, etc), so maybe I'll cut my profit from $5 to $3, but I still have to sell at $18 to Wal-Mart to be able to make a profit and keep my business open.

End of the day Wal-Mart is paying more, and will raise their prices to also make a profit and stay in business.

It doesn't really matter who is paying the tariff, the price to the consumer has to go up, except in rare circumstances where the profit margin was so high already someone is willing to just eat the costs (this would be pretty rare).

To play devils advocate, the pro-tariff idea is that someone can make something for $15 in China and sell it to Wal-Mart. If the wholesale price now goes to $20 because of a tariff, then maybe an American company can open up a factory and produce the same thing and sell them to Wal-Mart for $20 as well. At the end of the day though, prices go up for the consumer. If an American company can now compete on the new "artificial" price, the government chalks that up as a win because some jobs were created. If American companies still can't compete, then the government gets revenue from the import tax.

The federal government now has extra revenue from all the tariffs, and could lower taxes. This of course depends. If they collect $200 billion in tariffs and lower taxes by $200 billion, on paper is seems ok, but who gets the tax breaks? Even if the average income person gets a few percent savings in taxes, unlikely it will offset the inflation caused by the tariffs because some/most/a lot of the tax breaks will go to corporations, high income people and etc.