After keeping Kenyans guessing all year, Kibaki yesterday launched a new coalition, the Party of National Unity (PNU), to fight for a second term leading east Africa's largest economy.
Then the 75-year-old president -- who led opinion polls even before formally confirming he would run -- flew straight to Western Province, a region solidly behind the main opposition party Orange Democratic Movement (ODM).
Today, Kibaki was to unveil an energy production project at the Mumias sugar firm, inaugurate a road in the Mount Elgon area, and address a rally in a market-place.
Though officials said it was a ''working visit'', the trip was widely seen as the launch of grassroots campaigning.
Western Province is home to the Luhya tribe of ODM's No 2 Musalia Mudavadi. It is next door to the Luo region of Nyanza where ODM's charismatic leader and presidential candidate Raila Odinga has fanatic support.
''Kibaki has been sitting on the fence for a while, but now he has really started things off,'' said Kenyan analyst George Ogola, at Britain's University of Central Lancashire.
OPPOSITION VOWS ''GOOD FIGHT'' Kibaki, who comes from Kenya's largest tribe, the Kikuyu, united about half a dozen parties in his PNU coalition.
The alliance includes the Kenya African National Union (KANU) which held power for 24 years under Daniel arap Moi until it was defeated by Kibaki in 2002. The official leader of the opposition, KANU's Uhuru Kenyatta, ditched his own presidential ambitions to endorse Kibaki last week.
Kibaki's main remaining rival, Odinga, was in the United States meeting supporters during the Kenyan president's carefully choreographed speech to the nation yesterday.
He trails Kibaki in polls, 26 per cent to 42 per cent in the most recent national survey.
But in comments by phone to local media, he promised a ''good contest'' and urged Kibaki to fix a day for the poll, which is widely assumed to be planned for mid- or late December.
''We have beaten them before and we will do it again,'' he was quoted as saying in the Nairobi Star, referring to an Odinga-led 2005 referendum win against Kibaki's government.
Many of Kenya's 36 million people are impressed with the healthy economic growth under Kibaki, and the introduction of free primary education at the start of his rule.
But he gets lower marks from voters for failing to stamp out corruption or improve Kenya's often dreadful roads network.
Few, however, expect issues to trump tribal politics.
''Unfortunately ... what, at the moment, seems to matter, is the ethnicity of the three contenders,'' the Daily Nation wrote in an editorial, referring to a second opposition presidential candidate Kalonzo Musyoka, from the Kamba tribe.
That is ''one reason Kenyans keep voting for the wrong people, and sidelining those would bring fresh thinking.'' REUTERS SKB PM1428