Newsday: Everyone knows that President Donald Trump loves feuds, but one of his strangest targets is Amazon. Trump has repeatedly claimed that the retail giant is “scamming” the U.S. post office by taking advantage of the venerable institution’s low shipping rates.

Trump has long complained about the Washington Post, and Amazon founder Jeff Bezos’ ownership of it. But it’s still worth assessing the merits of the president’s argument. Is Amazon exploiting the post office?

No more than any other company in U.S. history. From the beginning, the post office has subsidized the cost of delivering all manner of goods, from newspapers to mail-order clothing, to encourage service to as many Americans as possible. It has done so in the name of knitting the nation together into a single, national market. Amazon is simply the latest in a long line of commercial interests to benefit.  Read more.