Another day, another Twitter rant about Amazon.com Inc. (AMZN) from the commander-in-chief.

Hours after tweeting an all-caps response to Iranian President Hassan Rouhani early Monday, July 23, President Donald Trump set his sights back on an old foe: Amazon.

"The Amazon Washington Post has gone crazy against me ever since they lost the Internet Tax Case in the U.S. Supreme Court two months ago," the president tweeted. "Next up is the U.S. Post Office which they use, at a fraction of real cost, as their 'delivery boy' for a BIG percentage of their packages."

The Amazon Washington Post has gone crazy against me ever since they lost the Internet Tax Case in the U.S. Supreme Court two months ago. Next up is the U.S. Post Office which they use, at a fraction of real cost, as their "delivery boy" for a BIG percentage of their packages....

— Donald J. Trump (@realDonaldTrump) July 23, 2018

Trump also accused The Washington Post of being a "lobbyist for Amazon" in a follow-up tweet.

....In my opinion the Washington Post is nothing more than an expensive (the paper loses a fortune) lobbyist for Amazon. Is it used as protection against antitrust claims which many feel should be brought?

— Donald J. Trump (@realDonaldTrump) July 23, 2018

Back in June, the Supreme Court ruled 5-4 that online vendors, such as Amazon, must collect state sales tax on online purchases even when they don't have a physical presence within the state. 

Trump has continued to slam the Seattle-based retailer over its heavy usage of the U.S. Postal Service, claiming in the past that taxpayers were footing the bill to deliver Amazon packages. Trump has blamed Amazon for losses at the USPS, alleging that the company pays too little for the high volume of packages that it has the post office deliver.

Experts have otherwise, noting that Amazon and other online retailers actually help the post office's finances a lot through their shipping activities.

Amazon fell 0.8% on Monday.

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