The ouster of Datuk Seri Mukhriz Mahathir as Kedah chief minister is the latest blow to the floundering efforts, spearheaded by his father Mahathir Mohamad, to topple Prime Minister Najib Razak.
The Kedah Umno rebellion against the son of Malaysia's longest-serving leader is widely seen as a proxy battle between the Premier and his predecessor.
Not only has Mr Mukhriz been removed, but he will also be replaced today by Datuk Ahmad Bashah Md Hanipah - a Najib loyalist despised by detractors for not completing secondary school - who led Kedah Umno leaders against Mr Mukhriz.
While Datuk Seri Najib's shake-up of his own party is creating disquiet outside of its leadership circles, within Umno's inner cabal, it is Tun Dr Mahathir's influence that has waned to insignificance.
"The Mahathir fear factor no longer exists in Umno, even in his home state," The Malaysian Insider wrote in an editorial of the man who himself withstood several challenges during his 22 years in power until 2003.
"He has become totally irrelevant against the exhibited power of incumbency," S. Rajaratnam School of International Studies (RSIS) fellow Oh Ei Sun told The Straits Times.
This is the latest of Mr Najib's (successful) moves to entrench himself in power.
Mr Mukhriz joins the likes of Umno deputy president Muhyiddin Yassin and vice-president Shafie Apdal in being sidelined from government after openly criticising the Premier over the financial scandals that surfaced last year.
In another positive development for Mr Najib, he was last week cleared by Attorney-General Apandi Ali of corruption over the US$681 million (S$972 million) found deposited into his personal bank accounts.
Tan Sri Apandi had said the money was a personal donation from the Saudi royal family, and that part of it - US$620 million - was returned in 2013 "because the sum was not utilised".
Mr Apandi, who was appointed Attorney-General in July last year after Mr Najib removed his predecessor, closed an investigation into the matter.
And while investigations into 1Malaysia Development Berhad's (1MDB) finances may be proceeding overseas, the Swiss Attorney-General's Office confirmed on Tuesday that the Premier was not a suspect in its corruption probe of the state investor's business.
Observers say legal challenges by Dr Mahathir's allies against Mr Apandi's refusal to charge Mr Najib over the money found in his personal bank accounts seem destined to fail.
This may be a new age for Malaysian politics, where Dr Mahathir is no longer kingmaker.
After seeing three of his own deputies fail to succeed him, his harsh criticism of the fourth's premiership led to Mr Najib taking power in 2009.
Dr Mahathir's son's appointment as Menteri Besar after the 2013 General Election was a concession by Mr Najib despite other Kedah leaders vying for the role.
The Prime Minister has now torn up that treaty, but only after Dr Mahathir set fire to it last year by calling for a change of leadership.
The former premier may still have a few tricks up his sleeve, but Mr Najib has shown his willingness to use the full extent of his executive power, no matter how controversial, to fend off and eliminate any threats.
In a parting shot at his last press conference as Menteri Besar yesterday, Mr Mukhriz said that "as long as Najib is still there, Umno is at its weakest point".
That may be true, but the Premier's strength appears even greater in comparison.
"People do care about the allegations against Najib, but if Mahathir can't do anything, what can others do? Impotence leads to resignation in a lot of people's minds," said Dr Oh from RSIS.
