This story, originally published in March 2018, was updated to reflect a statement from Patricof that was emailed to CNBC in January 2019.
Venture capitalist Alan Patricof says e-commerce giant Amazon is hurting small businesses.
@realDonaldTrump: I have stated my concerns with Amazon long before the Election. Unlike others, they pay little or no taxes to state & local governments, use our Postal System as their Delivery Boy (causing tremendous loss to the U.S.), and are putting many thousands of retailers out of business!
Axios reported Wednesday that the president has discussed altering Amazon's tax treatment because he's worried about mom-and-pop retailers being put out of business. Amazon's stock lost more than $50 billion in shareholder value at one point Wednesday.
"I don't agree with many things about our president, but that is one thing he brought up the other day that I think is a big concern," said Patricof, co-founder of the venerable Greycroft venture capital firm.
In a statement emailed to CNBC in January 2019 after the March report, Patricof wrote, "I do not support President Trump's opinions or views expressed about Amazon. However, small businesses and entrepreneurs fuel the growth of our society. We cannot afford to lose the thousands, if not millions, of people and businesses who are feeling the Amazon effect."
Patricof, a longtime donor to Hillary Clinton, said he puts Facebook, Alphabet's Google and Amazon "in the same category" in terms of their power because of the personal data they've acquired from users.
However, "Amazon [has] another issue of its monopoly," Patricof told CNBC's "Squawk Box." "It's more than data. It's taking over the whole retail world with what it's doing with small businesses."
White House press secretary Sarah Huckabee Sanders denied on Wednesday that the White House planned any imminent move against Amazon. "We have no announcement and no specific policies we are pushing for" related to Amazon, she said.
Patricof has criticized big tech companies before. Earlier in March, he told CNBC that the incredible influence that Facebook and Google have in society needs to be examined by regulators, calling the big tech companies "addictive" and "virtual monopolies."
Patricof said Thursday he expects there will be government regulation on tech companies in response to reports that Cambridge Analytica had harvested data from more than 50 million Facebook users without their permission.
Patricof has a 40-plus year career in venture capital, and his firm, Greycroft Partners, has more than $1 billion in assets under management. Some of the companies that Greycroft has backed include news organizations Axios and the Huffington Post, consumer bulk product shipper Boxed and cook-at-home service Plated.
Amazon did not respond to CNBC's request for comment.