You should not forget that Kibaki was beaten in 2007. Elected leaders are most vulnerable on re-election. Bush could have lost to Kerry; Bush snr Lost to Bill Clinton.
The temptation to rig one-self back is ever more present.
Why? One gets used to being praised and little if any unpleasant information reaches his ears. All those who make him unhappy are cut off and those who please him by dismissing the cannon shots approaching the Palace Gates as "the security guards farting aloud" are more than welcome and dominate. Kibaki got a rude shock when he was defeated in 2005 referendum. He did not see it coming. Thus he decided to rig 2007.
I do not see how Uhuru can avoid a runoff unless he carries out the same game as 2013 of topping up. CORD needs to stop topping up and maintain its vote in Nyanza and Western. Then kick Jubilee out of Coast and Kisii. If some votes come from RV, well and good but that would seal it.
Once there is a runoff, there are places that would change and the incumbent won't automatically gain. For example any Jubilee votes in Western and Coast would break for CORD.
About Kalonzo: If he does another Judas dance he would be finished. I doubt that he is that stupid. Mutua has no votes and would be another Kiema Kilonzo. Mutua will be check-mated by his Senator. I think Muthama would rather lose his seat than see Mutua in any public office. He has the resources and the determination to deliver. He can negotiate and pay off any support Mutua might get from Jubilee.
Ngilu is still their best man in Ukambani. As longs as Kalonzo is DP in CORD and Ngilu is an easily suspended CS, I think CORD will keep its vote at the last level perhaps with a 2% increase.
Yes a run-off will be the cliff-hanger coz it easier to rally Non-GEMA when the choice is binary.So what will Uhuru do...to ensure he doesn't go for run-off..he will swallow URP and make a deal with most likely Kalonzo or a Ukambani breakup(led by Mutua most likely)..that mean both Uhuru and Ruto (esp) will have to lose some posts like Speaker or Majority Leaders plus some cabinet . I think Western is lost forever as far as Jubilee are concerned. MaDVD/Wamalwa will not recover and might have to decamp to CORD allied coalition.
Anyway this is still Uhuru election. He just have some much leverage and patronage.
All that is needed to bring down Uhuru is a runoff. Anybody who manages to bring it about would have brought down Uhuru