Given all the good news, one might expect Kenya’s President Mwai Kibaki to be coasting to victory in national elections on Dec. 27. In fact, polls predict he’ll lose the vote to Raila Odinga: a two-plus-meter-tall populist better known for his purple suits and yellow Hummer than his reformist credentials. Odinga’s election would underscore the fact that Kenya’s renaissance, though real, has yet to reach most of its citizens. And on a deeper level, the popularity of Odinga—who as president could undermine Kibaki’s reforms—reflects the immaturity of Kenya’s voters, and their preference for tribal politics over quiet competence and a 21st-century state.

Kibaki’s likely defeat would be a bitter irony in a place that has come so far so fast. His government is “investing in [Kenyans’] quality of life, in their future,” says Achim Steiner, executive director of the U.N. Environment Program. Colin Bruce, country director for the World Bank, agrees, saying that Kenya is now one of sub-Saharan Africa’s hottest economies, with great growth potential thanks to its “culture of entrepreneurship, broad skills base [and] choice of development model.” Bruce argues that foreign investors share this optimism: “Some say that conditions hadn’t been this favorable for their business in over 40 years.”

Kibaki, 76, is Kenya’s first democratically elected leader, having replaced the authoritarian President Daniel Arap Moi in 2002. By privatizing industry, providing free primary education, cutting overall spending, creating business incentives and investing in IT (among other things), he helped build a knowledge-based economy that is fast becoming a regional hub for outsourcing, call centers and banking. Exports are at a record high for coffee, tea and flowers, a $600 million industry. And since 2002, 1.8 million new jobs have been created and per capita income has increased from $400 to $630, according to government figures.

During the same period, thanks to an aggressive awareness campaign, HIV prevalence has dropped from 13 to 6 percent—one of the lowest rates on the continent. “This is a very different country than it was five years ago,” says Bitange Ndemo, permanent secretary for the Ministry of Information and one of the army of well-educated Kenyans who left home under Moi but recently returned to work for their country.

Yet many of Kenya’s 34 million citizens have not yet felt the effects of the growth. The national poverty rate stands at 46 percent. Many government measures that would have touched the lives of ordinary Kenyans, such as infrastructure improvements, have yet to take shape. And Kibaki’s government has stumbled badly on corruption. In 2006, numerous cabinet members were accused of diverting tax money into phony companies. None were prosecuted, and most of those who resigned were later reinstated.

All this has helped Odinga, the main opposition candidate. The 61-year old politician served as minister of Roads under Kibaki, until a disagreement over constitutional reform led Odinga to break away and form his own party. Odinga has promised to improve Kenya’s decrepit streets and make other infrastructure fixes. His platform also has a distinctly populist bent: he’s said he’ll improve Nairobi’s notorious slums, provide low-cost housing and give cash transfers to the very poor. Odinga was polling at 46 percent to Kibaki’s 43 percent in mid-December.

Should he win, however, Odinga could spell real trouble. He has fair credentials as a democrat, having spent time in jail for standing up to the Moi regime during the 1980s and ’90s. Odinga has also managed, despite his age, to present himself as the choice of the next generation, filling his party, the Orange Democratic Movement (ODM), with young, well-educated, first-time candidates. “The fight now is about generational change and thinking outside the box,” says Najib Balala, 40, a former mayor of the port town of Mombasa and an ODM favorite.

But many economists and business leaders fear that Odinga’s main objectives are to increase his own power, wealth and prestige, and that if elected, he’ll make no more progress against corruption than did Kibaki (he’s surrounded himself with many of the same figures embroiled in past graft scandals). Perhaps even more worrisome, Odinga, who is a Luo, has based part of his appeal on the resentment shared by Kenya’s minority tribes against the dominant Kikuyus, . If elected, Odinga has suggested he’ll oust educated Kikuyus from government, decentralize power and build up Kenya’s Western province (Luo land) with money from the Central province (Kikuyu country)—steps that could increase the tribal tensions that paralyzed the country in years past.

Odinga argues that Kenya needs “radical change.” Kenyans, especially the poor, seem to agree. Certainly those who have to drink poisonous waters from the polluted Nairobi River every day have reason to feel this way. But the country has made huge progress under Kibaki, and more change is on the way. It’s far from clear whether Odinga will keep things moving in the right direction.