WASHINGTON, United States (AFP) — Donald Trump will have almost complete control over the levers of government — with only limited checks on his power — if Republicans add the House of Representatives to their White House and Senate victories.

He can rely on five key factors as he pushes through his populist America-First agenda:

– Democratic legitimacy –

Holding a more than five-million ballot lead on Thursday, Trump is set to emerge with an overwhelming victory in the popular vote against Democratic rival Kamala Harris.

He is on course to be the first Republican president in 20 years to achieve the feat.

The 78-year-old has already secured a clear majority in the Electoral College, which decides the president, with a margin that could still grow once the results in Arizona and Nevada are finalised.

If declared the winner in these two states, Donald Trump will have completed a clean sweep of the seven key battleground states.

Unlike with his victory in 2016, when Hillary Clinton won the popular vote, Trump will be able to claim greater legitimacy for pushing through his reformist agenda.

“America has given us a powerful and unprecedented mandate,” he declared on Wednesday.

Mid-term elections in two years will be the next opportunity for Democrats to check Trump’s power.

– An allied Congress? –

With counting still ongoing for about 30 out of the 435 seats, Republicans are leading the race to keep their slim majority in the House of Representatives.

Trump’s camp has already regained control of the Senate, with a few seats left to decide how large their upper chamber margin will be.

With a simple majority, Senate Republicans can confirm key executive figures and federal judges nominated by the president, as well as pass some reforms — such as tax cuts.

Having successfully purged the Republican Party of members not aligned with his “Make America Great Again” agenda, the president-elect is not expected to face significant internal resistance from sceptical lawmakers.

Most legislation however requires a supermajority of 60 votes to progress in the Senate — a figure Republicans will not reach.

– A government of loyalists –

As a political novice when he took office in 2017, Trump’s personnel choices largely consisted of seasoned Republican officials and military leaders.

Given his unpredictable behaviour, such moderating figures were dubbed by critics in the party and media as the “adults in the room”.

For his second term, the billionaire real estate mogul has made no secret of his intention to surround himself with loyalists.

He is widely expected to reward those who helped him campaign, including fellow billionaire Elon Musk and vaccine sceptic Robert F Kennedy Jr, among others.

Having also repeatedly clashed with the United States (US) Federal Reserve during his first term, Trump will have the opportunity in 2026 to appoint the successor to the current central bank chairman, Jerome Powell.

– A reshaped Supreme Court –

By appointing three deeply conservative Supreme Court justices during his first term, Trump helped anchor the country’s highest judicial power to the right.

With its six-three conservative majority, the court has recently given Republicans a slew of judicial victories — most notably the overturning of the nationwide right to abortion in 2022.

Two aging arch-conservatives, Clarence Thomas and Samuel Alito, aged 76 and 74 respectively, may consider retiring during Trump’s next term, enabling him to appoint two much younger replacements for life and cementing the court’s right-wing majority for decades.

– Immunity –

The Supreme Court ruled this summer that presidents enjoy absolute immunity for “official” acts in office — a landmark decision viewed as unleashing the power of the presidency.

The ruling stemmed from the federal criminal case brought against Trump over his attempts to overturn his 2020 loss to Joe Biden.

Now that Trump has once again become president-elect, that case and others are expected to be thrown out.