Ever since Amazon made its blockbuster bid for Whole Foods last week, there's been speculation over what the e-commerce powerhouse is going to try and buy next.

Chicago-based Grubhub, the online restaurant delivery service? Nordstrom department stores? Maybe it doubles down and buys another grocery store chain?

Those are intriguing questions, but here's another one: Is Amazon primed to violate federal antitrust laws designed to protect competition and consumers?

It's unlikely antitrust issues will derail Amazon's $13.7 billion attempt to purchase the upscale organic food store owner. Nonetheless, Amazon-related antitrust questions assuredly are going to surface as the Seattle-based online juggernaut expands its e-commerce reach, disrupts traditional business segments and gobbles up more companies.

"It's the most power-hungry push by a corporate boss I've ever seen," consumer advocate Ralph Nader said to me in reference to Amazon while urging federal regulators take a long, hard look at the company's business practices, starting with the Whole Foods transaction.

He's not alone in his concern, President Donald Trump apparently also harbors some Amazon antitrust anxiety.

While running for president last May, Trump told Fox News that Amazon CEO Jeff Bezos was concerned Trump would target Amazon, which Trump said has "a huge antitrust problem" but didn't get into specifics.

Since then, Trump has not alluded to Amazon's possible antitrust issues. The White House did not answer an email I sent asking about the president's campaign statement and what it might mean for the Amazon-Whole Foods deal.

Although taking a lower public profile recently, Nader is a consumer rights advocate, attorney, and former third-party presidential candidate. For decades, he's unflinchingly dueled with corporate America.

Now, he's raising the issue of Amazon's dominance.

Last year, Amazon had a 53 percent share of domestic e-commerce transactions, compared with 33 percent in 2015, according to California-based researcher Slice Intelligence. In 2016, 43 percent of all online retail purchases went through Amazon, Slice reports.

Its growth comes as e-commerce sales continue their ascent while traditional store and mall-based commerce tumble, prompting massive store closures and job losses.

Last year, an estimated $395 billion was spent on e-commerce and it's expected to grow annually, to $562 billion by 2020, according to New York-based FTI Consulting.

There are rumblings in legal and business circles that Amazon could potentially engage in so-called predatory pricing practices as it enters new markets or buys companies.

Simply stated, the online marketer's ability to charge much less for goods or delivery could run competitors out of business. Once the field is cleared, or Amazon dominates a business segment, it can boost prices at will and consumers will have fewer choices.

The sweep of Amazon's abilities are not fully appreciated, notes Lina M. Khan, a legal fellow with the Open Markets Program at the New America think tank. Khan wrote a paper titled "Amazon's Antitrust Paradox" that appeared this year in the Yale Law Journal.

She makes an extremely important point: Amazon is a lot more than a simple web retailer. It has the power to dominate internet commerce, which has the potential to hurt competition and the public at large.

"It is a marketing platform, a delivery and logistics network, a payment service, a credit lender, an auction house, a major book publisher, a producer of television and films, a fashion designer, a hardware manufacturer, and a leading provider of cloud server space and computing power," Khan writes.

Amazon correctly believes it has built a better online mousetrap and that free enterprise means being able to pursue opportunities, and taking the related risk, without government interference. It is a compelling argument.

Yet Amazon is in hypergrowth drive, one that's upending established industries and sparking community and job displacement.

I don't favor keeping traditional business ways or companies alive merely for old time's sake.

Still, the widespread ramifications of a powerful and expanding Amazon will need to be more closely examined by regulators, who have a mandate to protect the public interest amid the seismic changes underway in the new economy.

roreed@chicagotribune.com

Twitter @reedtribbiz