Joe Biden’s biggest supporters insist he is the most progressive US president since his reforming predecessor Franklin Delano Roosevelt.

Now Biden is trying to place himself in a tradition that includes not only FDR but also his cousin Theodore Roosevelt, the “trust buster” who instigated the break-up of Standard Oil in 1906, as he embarks on what the White House says will be a generational shift in US competition policy.

Biden’s backers say that the 72 actions in the presidential order signed on Friday — encompassing everything from airline ticketing policies to the importation of cheaper prescription drugs — constitute one of the most dramatic challenges to the power of large corporations since either Roosevelt.

They argue that while many of the individual items in the order might not seem that radical, the overall document is a blast against the Reaganite doctrine that corporations should be allowed to become as large as they like as long as consumers do not suffer.

Rather, Biden and his advisers want to make competition regulators account for the effect of corporate power not just on customers, but workers, suppliers and smaller rivals too.

“This is the biggest change in competition policy since [Ronald] Reagan came in,” said Barry Lynn, director of the Open Markets Institute and one of a small group of leftwing thinkers who influenced last week’s order. “For the first time in 50 years we are really getting down to the nuts and bolts of the political economy.”

Heather Boushey, a member of Biden’s Council of Economic Advisers, said: “Making sure that the little guy has the opportunity to engage in the economy; that there is an open and level playing field — these are important values that [the president] brought to all of our conversations.”

The order included instructions and guidance to several government agencies urging them to take action in a range of sectors. For instance, the president told the Food and Drug Administration to work with states to find a way to safely import drugs from Canada in an attempt to undercut prices charged by drugmakers in the US.

Such a move is not new, however. The US health department issued a rule last year while Donald Trump was still in office allowing for the importation of drugs from Canada. But the power to authorise specific purchase proposals from states and other health authorities rests with the FDA, which rarely grants such approvals.

Biden also “encouraged” the Federal Trade Commission to explore how it can curtail the use of so-called non-compete clauses that stop workers moving from one employer to a rival. Such clauses have been used by companies like Amazon, which say they need them to protect trade secrets. But the president says they have been abused to keep wages down.

Non-compete clauses are restricted in certain states but Democrats on the FTC believe they have the legal authority to set federal limits, too. The question now is whether the commission chooses to ban their use outright, or take more limited action by curbing them for lower-wage workers alone.

“The order does not say ban, it says curtail,” said one senior White House official. “So it does leave the door open to some kind of more limited action.”

Some critics say the White House does not have to power to drive through such a broad reshaping of antitrust policy, pointing out that Trump was unable to follow through on his repeated pledge to lower drug prices with measures, including reimportation.

Others argue the package is a mixture of minor fixes and more ambitious policy measures that are unlikely to withstand scrutiny from Congress or the courts.

Rob Atkinson, president of Information Technology and Innovation Foundation, a tech industry backed think-tank, said: “A lot of these measures are small beer. Now you will know each of the costs involved in an airline ticket. So what?”

However, taken in its entirety, the order sends a signal to the thousands of government officials involved in shaping government policy.

For instance, it instructs the agriculture secretary to “reinforce” the view that it is illegal for large agricultural companies to give preference to one farmer over another, even if there is no industry-wide effect.

It also encourages the FTC to account for “unfair data collection and surveillance practices” by large technology companies when deciding whether to take enforcement action against them.

These items reflect the view of many progressives that regulators have been too reluctant to take antitrust action where they cannot prove any obvious harm to consumers, such as price rises.

But judges have often been sceptical of such an interpretation of existing antitrust laws. Last month, a federal judge dismissed a complaint by the FTC against Facebook because it said regulators had not done enough to prove the company was dominant in its market.

Many expect a stringent test of this theory if Lina Khan, the Biden-appointed head of the FTC, launches a case against Amazon, a company she has frequently criticised in the past for abusing its market power.

If Khan succeeds in breaking up Facebook or Amazon, it is likely to be remembered in a similar light to the Standard Oil case brought by the administration of Theodore Roosevelt.

But even if she and the Biden administration fail to win a landmark case, many supporters believe the debate around the power of US corporations will be forever changed.

Sarah Miller, the executive director of the American Economic Liberties Project, said: “This order . . . breaks from 40 years of consensus about how the government should interact with corporations.

“It is all the more substantial because it was Joe Biden, and not one of the Democrats we think of as part of the progressive wing, who signed it.”