One of the unique aspects of Washington life is a Senate "vote-a-rama," in which the upper house of Congress tortures itself by pulling a marathon all-nighter of speeches, amendments and votes on a critical bill.

The Senate has just endured the usual melange of horrors before passing US President Donald Trump's massive tax and spending agenda - the One Big Beautiful Bill Act.

The process was a mess and the final result was tight: 51-50 after Vice President JD Vance broke the tie. But it landed another huge political win for Trump.

It will likely be no different when the bill hits the House of Representatives, before being signed into law, maybe as soon as July 4 - Independence Day.

Using the momentum from his bunker-busting strike on Iran's nuclear weapons program, Trump pressured wavering congressional Republicans to toe the line and support the package.

The bill includes a continuation of Trump's tax cuts from his first term, which were set to expire next year. They are being portrayed as new tax relief, even though American tax policy remains the same because of arcane budget process rules in Congress.

Trump included a provision eliminating taxes on tips and overtime, which will further endear him to many working Americans, particularly those in private sector unions and food services.

The bill also provides more funding for border security and a US$150 billion (A$227 billion) boost to defence spending, which will soon be tracking at more than US$1 trillion (A$1.51 trillion) per year.

Other measures include work requirements for government health care recipients and cuts to two major safety net programs, including Medicaid.

As a budget bill, there are some limits to what provisions can be included, but the Trump team was able to shoehorn nearly all of his domestic agenda into this bill - hence the absurd title.

All of this means Trump can get what he wants if he keeps Republicans united, as no Democrats are needed to pass the bill into law.

The "big beautiful bill" provides some political opportunities to Trump's opponents.

The Democrats have fought the bill at every step, saying the "tax cuts" only benefit rich people while the health care cuts will have severe consequences for the working poor.

They can plausibly accuse Republicans of cutting taxes for the wealthy. However, the tax cuts on tips and overtime somewhat mitigate that attack.

The Democrats have also highlighted the impact of the bill on America's national debt, which is at historically high levels. But this attack has only highly limited benefits for the party, which is not known for its own spending restraint.

Nevertheless, Trump's bill is so far winning passage, often by the thinnest possible margins, at every stage of the wonderfully convoluted American legislative process.

The victory in the Senate has not come without some costs, especially given the way it has exacerbated Trump's explosive feud with Elon Musk.

The public divorce between Trump and his former "First Friend" has been an ongoing soap opera. Saturation media coverage of the squabble between the world's richest man and its most powerful, has featured threats, accusations, name-calling, and physical confrontations.

Once it became clear Trump's One Big Beautiful Bill did not include significant budget cuts, Musk turned on his patron and severely criticised the legislative effort, as "political suicide" for the Republican Party:

It will destroy millions of jobs in America and cause immense strategic harm to our country

Although the two men patched things up a few weeks ago, the bitter feud has erupted again with the bill's passage though the Senate.

Musk says the bill is "utterly insane and destructive" and is vowing political retribution on Republicans who voted for it:

In turn, Trump has threatened to deport Musk back to his birth country of South Africa and turn the Department of Government Efficiency (DOGE) loose on Musk's companies that have contracts with the government, including SpaceX, which is a necessary component of the American space program.

Musk's tantrums are unlikely to lead to real political problems for Trump, given many congressional Republicans continue to rely on the president for support.

They will not be tempted to support Musk no matter how much he threatens them.

The president has managed his legislative strategy to near perfection.

Trump and his team used the DOGE process to give political cover to fiscal conservatives to vote with him on the bill. Even the breach with Musk didn't change this dynamic much.

At the end of it all, Trump has been able to enforce discipline in his own party and get what he needed from Congress.

When Trump signs his big beautiful bill into law, it will be another political victory for the president.