• Musk’s own companies — including Tesla Inc. and SpaceX — have enjoyed billion of dollars in federal benefits through the years, including electric vehicle tax credits and infrastructure investments, further underscoring the difficulty of implementing a $2 trillion cut.

Elon Musk is heading to the Capitol on Thursday to stoke congressional enthusiasm for his ambitious effort to slash at least $2 trillion from the federal budget, a level of austerity unprecedented in the US since the winding down of World War II.

Musk and his partner in the initiative, former Republican presidential candidate Vivek Ramaswamy, plan to meet with groups of lawmakers, followed by a session all Republican House members have been invited to, said GOP Representative Marjorie Taylor Greene who will lead a new House subcommittee devoted to the effort.

Musk, the world’s richest man and a formidable financial backer of President-elect Donald Trump, has thrown his celebrity into the effort, relentlessly promoting what he has styled as the “Department of Government Efficiency” or “DOGE” in a reference to cryptocurrency Dogecoin that he periodically promotes.

Despite the name, that department doesn’t exist. As such, Musk and Ramaswamy will operate outside the government as advisers.

Attempts by previous presidents to cut federal spending were frustrated by the myriad parochial interests of members of Congress. This time around, many Republican lawmakers are clearly on board with a key Trump campaign pledge.

Greene on Wednesday anticipated the potential fiscal accomplishment as “really for the American people.”

Musk has practically become Trump’s right-hand man who sits in on the president-elect’s calls with foreign leaders, weighs in on cabinet picks and clearly has the incoming president’s ear. He has considerable influence with Republican lawmakers.

Musk’s target to cut $2 trillion exceeds the amount Congress spends annually on government agency operations, including defense. It would likely require making significant cuts to popular entitlement programs such as Social Security, Medicare, Medicaid and veterans’ benefits.

Last fiscal year, the government spent more than $6.75 trillion, with more than $5.3 trillion of that coming from Social Security, health care, defense and veterans’ benefits — all of which are politically fraught and notoriously difficult to convince Congress to cut — as well as interest on the debt.

One option the DOGE duo and Trump have promoted: not spending all of the money Congress has appropriated via a process known as impoundment. That has already faced bipartisan blowback on Capitol Hill, where lawmakers like top Republican appropriator Susan Collins and others fiercely guard Congress’s power of the purse and support the 1974 law restricting the practice.