Maybe Trump wouldn't mind if Walmart (WMT - Get Report) buys Humana (HUM - Get Report) to try and outflank the beast that is Amazon (AMZN - Get Report) . 

President Trump continued his week long assault on the eCommerce king on Saturday via his second favorite place in the world (first one: golf course), Twitter. "While we are on the subject, it is reported that the U.S. Post Office will lose $1.50 on average for each package it delivers for Amazon. That amounts to Billions of Dollars," Trump tweeted. "If the P.O. "increased its parcel rates, Amazon's shipping costs would rise by $2.6 Billion." This Post Office scam must stop. Amazon must pay real costs (and taxes) now!"

On Wednesday, an Axios report citing unnamed sources said the president has wondered if there's a way to "go after Amazon with antitrust or competition law." Trump reportedly wants to knock Amazon's power by altering its tax treatment. 

Amid the fresh attacks from the commander-in-chief, Amazon's stock has shed about 6% over the past five sessions. 

As TheStreet has written lately, Amazon is unlikely to skirt the heavy hand of the government, in some form, for much longer. 

While we are on the subject, it is reported that the U.S. Post Office will lose $1.50 on average for each package it delivers for Amazon. That amounts to Billions of Dollars. The Failing N.Y. Times reports that "the size of the company's lobbying staff has ballooned," and that...

— Donald J. Trump (@realDonaldTrump) March 31, 2018

...does not include the Fake Washington Post, which is used as a "lobbyist" and should so REGISTER. If the P.O. "increased its parcel rates, Amazon's shipping costs would rise by $2.6 Billion." This Post Office scam must stop. Amazon must pay real costs (and taxes) now!

— Donald J. Trump (@realDonaldTrump) March 31, 2018

Amazon is the fastest growing major retailer in the U.S., and outpaced eCommerce's growth as a whole in early 2017, Yale Law statistics show. The company's growth plans have caused shock-waves throughout many industries, notably healthcare, where big players fear Amazon's price-slashing and speed. In response, CVS Health (CVS - Get Report) is nearing a deal to buy health insurer Aetna (AET . Walgreens Boots Alliance (WBA - Get Report) is reportedly looking to buy the rest of drug wholesaler AmerisourceBergen (AB - Get Report) C it doesn't own.

In retail, Target (TGT - Get Report)  has been linked to showing interest in buying supermarket leader Kroger (KR - Get Report) .

"We cannot cognize the potential harms to competition posed by Amazon's dominance if we measure competition primarily through price and output," Lina M. Khan wrote in a Yale Law Review note last year. "Specifically, the current doctrine underappreciates the risk of predatory pricing and how integration across distinct business lines may prove anticompetitive."

Edward Duffy, an antitrust lawyer and commercial litigator at Reed Smith LLP, tells TheStreet that the Department of Justice or FTC could challenge a particular industry-specific practice that may affect the tech and data-driven sectors that might have previously gone unnoticed or unregulated.

"For a while there can be a lack of enforcement," Duffy says. "But that can change quickly."

If Trump keeps tweeting, that enforcement could come quicker than some investors think. 

-Kinsey Grant contributed to this story. 

Jim Cramer and the Action Alerts Plus team hold a position in Amazon for their Action Alerts Plus charitable trust portfolio. Want to be alerted before Jim Cramer buys or sells Amazon? Learn more now.