Reince Priebus’s departure as chief of staff marks the latest and most significant step in the White House purge of party loyalists closely tied to the Republican national committee.

Priebus leaves the White House less than a day after the failure of healthcare reform in the Senate.

The former chair of the Republican National Committee, who had risen through the party machine, had been hired as chief of staff in part because of his relationship with the Republican leadership on Capitol Hill, in particular Paul Ryan, the House speaker.

But the failure of efforts to repeal and replace the Affordable Care Act, something which never particularly enthused Trump, helped seal the fate of the long embattled Priebus, who had faced constant attack from his new colleague, communications director Anthony Scaramucci.

Priebus’s departure – announced by the president on Twitter – comes a week after embattled White House spokesman Sean Spicer finally stepped down. However, the move had long been in the works, with one source telling the Guardian that Trump had decided on replacing Priebus with John Kelly two weeks ago.

Spicer, who had long worked for Priebus at the RNC, had stepped down after Trump brought Scaramucci on staff.

Scaramucci promptly fired one RNC holdover on the communications staff, and immediately set about bad-mouthing Priebus on television and describing him as a “paranoid schizophrenic” to a reporter for the New Yorker. Scaramucci had claimed he and Priebus were like brothers – Cain and Abel – neglecting to note how that sibling rivalry ended with one murdering the other.

His replacement by Kelly, a political outsider who had served as a general in the US marines before being named Homeland Security secretary by Trump marks the transition to a White House fully defined by the President’s admiration for businessmen and generals.

It also means that Trump’s administration is now almost totally devoid of establishment Republicans. Instead, it includes a mix of ex-Democrats such as his son-in-law Jared Kushner and Gary Cohn, the former president of Goldman Sachs, as well as fervent nationalists such as Steve Bannon and speechwriter Stephen Miller.

Priebus’s dismissal is also unlikely to ease Trump’s relationships on Capitol Hill, particularly in the House of Representatives, which has proven far more amenable to his agenda than the Senate. Ryan is a longtime Priebus ally dating back to their rise in Wisconsin Republican politics, and Ryan vocally backed Priebus on Thursday, telling reporters: “Reince is doing a fantastic job at the White House and I believe he has the president’s confidence.”