By switching Deputy Presidents from Rigathi Gachagua to Kithure Kindiki, William Ruto has strengthened his position to avoid a serious challenge to a second term from 2027.
Prior to the 2010 reform Constitution resulting from the 2008 “Peace Deal” and National Accord as a consequence of the Post Election Violence from Mwai Kibaki’s rigged re-election, Kenya had Vice Presidents who were understood to serve at the President’s pleasure.
This was a core feature of one-party KANU rule under Jomo Kenyatta and Daniel arap Moi. Mwai Kibaki himself served as Moi’s initial Vice President in 1978 and continued in office as one-party KANU rule moved from de facto to de jure. In 1988 he was precipitously demoted by Moi.
After the Kibaki-controlled Election Commission of Kenya gave a re-election certificate to Kibaki and his dusk swearing in that evening of December 30, 2007, Kibaki appointed “third party” (ODM-K) presidential candidate Kalonzo Musyoka as his new Vice President (Kenya’s 10th) and Minister of Home Affairs on January 8 as the country was engulfed in violence by Kibaki’s security forces, by organized ethnic militias and spontaneously. The Musyoka V.P. appointment accompanied a “Half Cabinet” that included key Kibaki supporters such as Uhuru Kenyatta.
The sitting Vice President from Kibaki’s re-election, Moody Awori, was more or less ignored.
During Kibaki’s second term, with the rest of the Cabinet filled out under the National Accord, Musyoka as Vice President had ambiguous status relative to the new Prime Minister, Raila Odinga.
When the final version of the proposed new constitution emerged from the backroom negotiations at Naivasha between the factions in the so-called Government of National Unity, the positions of Prime Minister and Vice President were eliminated in favor of a Deputy President. William Ruto was the primary leader of opposition to the new draft constitution in the 2010 referendum but carried only his core ethnic base and lost by a landslide nationwide.
Elected as one half of the UhuRuto “coalition of the killing” (by reputation and as alleged in the failed ICC prosecution) in 2013 with a tiny official margin over the requisite 50% (as determined by the IEBC in the wake of the corrupt voter identification and poll book procurements and failure of the electronic results transmission system), Ruto became Kenya’s first Deputy President. And perhaps functionally it’s last, so long as Presidents control Parliament and are willing to use impeachment to “switch horses”.

See The Star, “Nyoro faces axe as Ruto plots major parliament purge” to reward allies and punish independents following impeachment.