His allies have openly pushed him to plan his succession. These calls will grow louder now that the AU's Executive Council cleared the way for his nomination for the AUC's top job.
The race within Azimio has always seemed to be Wiper Leader Kalonzo Musyoka's for the taking, despite him being third in the coalition's pecking order behind Raila and Narc Kenya leader Martha Karua.
Karua, Raila's running mate in the 2022 elections and Azimio's deputy party leader, has been missing in action as Kalonzo capitalises, presenting himself as Raila's heir-apparent.
On several occasions, insiders have revealed that Kalonzo will be the opposition's candidate in the 2027 election, even as Raila stays tight-lipped about his retirement from Kenyan politics.
In recent weeks, the former vice president has seemed to be stepping up as the coalition's voice and face, challenging the government's policies, even as he has held rallies to popularise his presidential bid.
Other Azimio principals have appeared to coalesce around the Wiper leader as they pressure Raila to hand over the baton.
The former premier faces similar pressure within ODM, where his two deputies are publicly tussling over control. Former governors Wycliffe Oparanya (Kakamega) and Hassan Joho (Mombasa), both of whom Raila said could lead the country's second-largest party, are keen to replace their boss.
Their supremacy contest has created factions within ODM. Politicians from Western Kenya favour Oparanya, while those from the Coast and North Eastern regions champion Joho's claim to the throne.
Joho recently met Narok Senator Ledama ole Kina and lawmakers Junet Mohamed (Suna East) and Babu Owino (Embakasi East), all of whom are said to be in the former governor's faction.
Oparanya also recently met businessman Jimi Wanjigi, a presidential hopeful, amid talk that he could deputise Wanjigi in the next elections. The power broker met Raila nearly two months ago, with his meeting with Oparanya seen as a follow-up to that.
The former Kakamega governor is also seen as a potential running mate to Kalonzo, with highly-placed sources stating that the Wiper leader could pick a running mate from Western Kenya. He is, however, facing competition from former Defence Cabinet Secretary Eugene Wamalwa and Nairobi Senator Edwin Sifuna.
Many in favour of Oparanya fault Joho for going missing at critical points, only resurfacing when there are spoils to be shared. He has, however, defended his actions, stating that Raila was always aware of his every move.
Not everyone subscribes to the two factions. An example is Wajir Governor Ahmed Jiir, who, during a recent ODM recruitment drive in his county, said "we will not let Joho and Oparanya wreck ODM."
Saboti MP Caleb Amisi has also dismissed the two factions as "lacking any ideology or democratic foundation", saying talk about Raila's succession was premature.
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"Time is not ripe for such until Baba is comfortably on the AUC seat. What they are doing is akin to inheriting your father's property while he is still alive. The factions are immature and formed out of the fear of the unknown because those forming them know without Baba their political careers are doomed," said Amisi.
Others, such as National Assembly Minority Leader Opiyo Wandayi, believe it is all square within the party. In a press briefing last Monday, the Ugunja Member of Parliament said he was ready to take up the leadership role if Raila were to retire from politics.
"In the event Raila chooses to step aside upon clinching the African Union chairmanship, the field will be open to everyone," said Wandayi.
Younger ODM lawmakers, and by extension Azimio, are also uniting into their faction. Sources told The Sunday Standard that this group feels the time is ripe for a generational change within the opposition.
"We want a generational change that can inspire young people into our party. You saw many of them did not vote in the last election. The old guard should go to Addis with Baba," said a source who requested anonymity.
Amisi concurred and stated that ODM needs a "fresh, energetic, enthusiastic and charismatic leadership that can take over from Baba."
"Immediately after Baba takes over at AU, the younger generation, me included, will assume the party's leadership. I will be going for Oparanya's position," said Amisi.
The generational change push has always featured within ODM and could influence Kalonzo's pick of a running mate, should Azimio back him for the presidency.
In the past, agitation by younger politicians has enjoyed some success. In 2014, Sports Cabinet Secretary Ababu Namwamba (then Budalangi MP) clinched the ODM secretary general position in a successful coup against the old guard.
He was part of Joho's faction that demanded influence from younger politicians. Joho would rise to become the deputy party leader.
In 2018, Namwamba lost the plum role to a younger Sifuna, who had himself staged an unsuccessful coup two years earlier, with ODM opting for former senator Agnes Zani.
University lecturer Timothy Onduru says that change "will not come overnight".
"In any case, the old blood will still be needed to guide their younger colleagues," said Dr Onduru, who teaches history at Moi University, warning that the factions risk disintegrating the party.
"Raila has curved a national and regional look and it will be difficult to emulate that," he added.
Gitile Naituli, a lecturer at the Multimedia University of Kenya, challenged the younger politicians to differentiate themselves from the pack.
"They should provide leadership and start talking about national issues," Prof Naituli stated, adding that waiting for Raila to plan his succession was futile.
"In political leadership, succession is never planned. It is only planned in management. Leadership is taken by those who most desire to lead and have a vision that the society buys into," he added. "Leaders emerge by creating a need for themselves and having a vision."
The battle is equally fierce in Nyanza. Months ago, Siaya Senator Oburu Oginga endorsed Wandayi to lead the region. Raila's wife Ida Odinga recently backed Nominated MP John Mbadi for the role.
The pair, both staunch allies of the former premier, has engaged in supremacy battles in the past. But they are not sitting pretty as other politicians seek to control the region that puts all its votes in one basket.
Within the opposition, Homa Bay Governor Gladys Wanga and Embakasi East MP Babu Owino are seen as potential challengers to the throne.
Interior Principal Secretary Raymond Omollo is also making his mark within the region but he faces competition from Information Communication and Technology Cabinet Secretary Edwin Owalo.
Prof Naituli believes Raila's imminent exit will "open up the field everywhere in the country, not just in Nyanza", for new leaders to emerge.
But Dr Onduru argued that chances of inheriting the Azimio leader's traditional base were slim "as long as Raila is still in the picture."
"Moving to AU will not reduce his influence in Luo land... and he has every right to resign in 2027 and contest the presidency. Political decisions are personal and he can make such a decision. In ODM, he has two deputies who can take over in his absence but it is better if one is elected through a delegates system," he stated.