Donald Trump is still a month away from returning to the White House and already his relationship with Republicans on Capitol Hill is fraying, signalling trouble ahead for both sides.

The president-elect’s inability to intimidate members of his own party in the House to back a spending resolution just to keep the government open ahead of a midnight shutdown surely has implications for his ability to drive through his ambitious agenda in the face of tiny majorities in both congressional chambers once he returns to office.

The imbroglio also demonstrates the poisoned chalice that awaits the House speaker, Mike Johnson, as he seeks to balance that majority – which will effectively shrink to just one for several months following the resignations of members tapped to fill Trump’s cabinet – against the demands of the incoming president and his now ubiquitous “government efficiency” guru, the billionaire Elon Musk. Johnson himself might lose his grip on the speaker’s gavel as he faces a speakership election on 3 January, with at least one colleague already coming out against him for how he has handled negotiations over the spending deal.

Trump will return to the Oval Office on 20 January with an in tray that includes extending his historically large 2017 tax cut and a promise to start expelling an estimated 11 million undocumented immigrants. He knows he will need all the congressional support he can get.

But that knowledge is now tempered by the awareness that this support is not guaranteed, and he has threatened recalcitrant House members to primary challenges to keep them in line.

Most of the Republicans who voted, in defiance of Trump’s wishes, against a bill that would have raised the US debt ceiling are impervious to such threats because they won thumping majorities in November’s election.

One of the 38 refuseniks, Thomas Massie of Kentucky, was once called a “third-rate grandstander” by Trump during his first presidency after voting against coronavirus relief, but still won re-election twice after the president-elect said voters should “throw him out of the Republican party”.

Simply put, if those who defied Trump on Thursday can do it once, they can do it again - especially given that most of them already have their Maga credentials as members of the hard-right Freedom caucus.

As Trump approaches 2025 and his second inauguration, another concern may intrude on his thoughts – the insidious power of Musk, who egged him on to reject the original three-month continuing resolution spending agreement cobbled together by Johnson.

The president-elect is trying to pin any looming Christmas season government shutdown on the still-in-office, but increasingly low-profile, Joe Biden.

But with social media references to “President Musk” on the rise – and the SpaceX and Tesla entrepreneur’s financial contribution to Trump’s election victory well known – the impression of political impotence might not be restricted to Biden.

Musk’s continued presence in the political limelight may easily begin to grate on the famously thin-skinned president-elect who is not known for a willingness to share it.