The closeness of the election is somewhat obscured now by the “winner take all” nature of Kenya politics and the quick consolidation of power by Ruto, but it really was very tight under any view. No disrespect to Martha Karua intended because her choice did help revitalize Raila’s campaign when he had persistently trailed in the polls throughout and then moved ahead when she was tapped.
Nonetheless, all politics in Kenya is local/tribal and she was undoubtedly picked in part to try to offset Raila’s weakness versus Ruto in the core Kikuyu old Central Province, as well as a play for “good governance” support from the “international community” and civil society (which had adopted Karua for a variety of reasons in recent years in spite of her understood role as a Kibaki Kikuyu hardliner opposed to the peace deal and power sharing in the 2007-08 ECK and PEV crisis).
At the end of the day, I think Karua was respected but not highly popular, whereas Ngilu was less respected internationally, and perhaps among some parts of Kenya’s more intellectual class, but more popular as a politician.
One thing that I am guessing that happened is that Raila overestimated the practical value of going with a “Good Government” choice in terms of support from Washington and London, and otherwise from “the Western donors”, just as he overestimated the transferability of the support that Kenyatta had in those capitals to him. I think he just may have been behind the times on this: there were years when Ruto or a candidate with his profile would have drawn active criticism internationally for corruption but 2022 was just not such a year for a variety of reasons. Likewise people in Washington that considered Ruto “dangerous” as late as a couple of years ago because of his role in the PEV seem to have gotten over it once they saw him as the long-established frontrunner in the polls and BBI not catching on. I think many were unsure whether Kenyatta was really going to follow through on supporting Raila which made it that much easier to rationalize a Ruto presidency.
“On the ground” among Kenyan voters, Raila could not pull off running a traditional opposition anti-corruption oriented campaign after several years of the handshake and clearly counting on Kenyatta’s support. Too much cognitive dissonance, especially after getting beat in the Courts on a BBI that got larded up and bogged down to the point of becoming notably unpopular in its own right. On that front, the Karua pick seems to have proven too late and too out of step with the messaging from Raila’s other coalition heavyweights.
Given that he was behind in the polls and needed a spark, I do think choosing a woman made sense, but Ngilu as a more traditional Kenyan politician who was a current office holder and a long established vote getter from a “swing” region and ethnicity might have fit the bill quite a bit better. A more obvious choice to match up versus Mudavadi and Wetagula on Ruto’s side and a more congruous fit with the rest the established heavyweights on the Azimio team.