President Trump has blasted Amazon the last few days, alleging the e-commerce giant is taking advantage of the U.S. Postal Service and failing to pay enough in state and local taxes. Mr. Trump claims his criticisms of Amazon long predate his election.

But Mr. Trump's presidential campaign relied on Amazon for office supplies regularly, spending $158,498.41 in 379 transactions labeled as office supply purchases in 2015 and 2016, according to Federal Election Commission records reviewed by CBS News. In the average transaction, Mr. Trump's campaign spent $418.20, and the most the campaign spent in a single transaction was $3,890. The Donald J. Trump for President committee continued to use Amazon well after the election, spending more than $2,000 in 2017, FEC records show.

The president's claim that he has long voiced concerns with Amazon, since well before the election, doesn't seem to have deterred his campaign from — as many political campaigns, businesses and American families do — relying on the giant retailer for supplies regularly. The Consumer Intelligence Research Partners (CIRP) estimates that the average Amazon Prime member spends $1,300 on Amazon in a year, compared with $700 a year for the average non-Amazon Prime member.

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! — Donald J. Trump (@realDonaldTrump) March 29, 2018

The White House has insisted Mr. Trump's criticisms of Amazon are strictly policy-related. But Mr. Trump expanded that attack on Saturday morning, claiming, without any evidence, that Amazon is using the Washington Post as a "lobbyist." Mr. Trump said the newspaper should "REGISTER" as such. The president's decision to bring the "fake" Washington Post into the conversation makes it more difficult for the White House to argue that Mr. Trump's concerns are strictly related to policy and to Amazon specifically. Both Amazon and the Washington Post are owned by billionaire Jeff Bezos.

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

Mr. Trump continues to insist Amazon is losing money the Postal Service should receive. So, is that the case? For one thing, the postal service has been losing money for 11 straight years, largely attributable to pension and health care costs. And a Citigroup analysis notes that the actual cost of shipping packages is roughly 50 percent more than what it currently charges. Amazon ships enough packages through the postal office to qualify for a bulk rate.