The two leading candidates in Kenya's December 27 presidential elections are everywhere: in full page photos on newspaper covers; staring down from Nairobi billboards; speaking on radio advertisements; and campaigning on the popular nightly news. But as Derek Kilner reports from Nairobi, President Mwai Kibaki and challenger Raila Odinga were familiar to Kenyan voters well before the campaign season got under way.

Mwai Kibaki is now in his fourth presidential run, Raila Odinga in his second and even before the introduction of multi-party politics in 1992, both had well-established political records.

President Kibaki, 76, has been a member of parliament since before Kenya gained independence in 1963. He held a series of Cabinet positions in the governments of Presidents Jomo Kenyatta and Daniel Arap Moi, serving as vice president from 1978 to 1988.

But with the introduction of multiple parties in 1992, Mr. Kibaki started the opposition Democratic Party, finishing third in 1992 presidential elections, and second in 1997, before leading the National Rainbow Coalition to victory in 2002 over the ruling Kenya Africa National Union Party that had ruled since independence.

In a testament to Kenya's rapidly-shifting political alliances, Mr. Kibaki's 2002 opponent, Uhuru Kenyatta is now backing the president, as is former president Moi.

Mr. Odinga has served in the Moi and Kibaki governments.

But his political career has been defined by opposition, going back to his father. Oginga Odinga served as Kenya's first vice president, but was jailed for two years after breaking with President Kenyatta, and remained an opposition figure under President Moi.

Raila Odinga began serving in parliament in 1975, but after participating in a 1982 coup attempt against Moi, he spent the better part of the next decade in prison. Odinga returned to parliament with the introduction of multi-party politics in 1992. After an unsuccessful bid for the presidency in 1997, he joined President Moi's Cabinet.

In 2002, Mr. Odinga helped launch the National Rainbow Coalition, along with Mr. Kibaki and Kalonzo Musyoka, who is running third in this year's elections. Mr. Odinga was instrumental in President Kibaki's 2002 victory.

But he broke with the president over a proposed constitution that was rejected in a 2005 referendum. Mr. Odinga became the leading force behind the Orange Democratic Movement that opposed the proposed constitution and has effectively been running for the presidency ever since.

Many analysts see few major differences in the policies the candidates will pursue if elected. But as analyst Mutahi Ngunyi tells VOA, the candidates differ dramatically in their presentation and rhetoric.

"The difference between the two is that Kibaki appeals to our heads, Raila appeals to our hearts. Raila is charismatic. Kibaki is less than charismatic. Kibaki will appeal to the intellectuals by having very good arguments, making good presentations that appeal to us intellectually. That is why he has a lot of support from intellectuals," said Ngunyi.

Mr. Odinga, who made waves in the media earlier this year when he purchased a Hummer, is often decked out in his party's bright orange colors and sometimes sports a cowboy hat. President Kibaki, meanwhile, gazes calmly from large Nairobi billboards, dressed smartly in a suit and tie.

Mr. Kibaki came to power in 2002 as the candidate that ended four decades of rule by KANU, this time around he is the candidate of stability. He highlights Kenya's strong economic growth and urges voters to let him build on achievements from his first term in office, including the introduction of free primary education.

But President Kibaki still sometimes employs the rhetoric of change.

"I have in mind the kind of Kenya we want to build and I am not talking about the history of Kenya that is in the past," he says. "I am thinking of the new Kenya from this election the Kenya we want to build the Kenya we want to have the Kenya we are looking forward to above all the Kenya we would like our children to inherit."

Mr. Kibaki recently pledged that he would appoint a Cabinet free of corruption and deliver a new constitution. Odinga supporters counter that these are the same pledges that Kibaki made five years ago and the fact that he is repeating them is evidence that he has failed to deliver.

While Mr. Odinga has been a successful businessman his campaign rhetoric has focused on reducing inequality among groups and regions. Kibaki support is concentrated in Central Province, Kenya's wealthiest. The Odinga base lies in Kenya's poorest province, Nyanza, in Kenya's west.

Mr. Odinga calls for decentralization of government and resources have also earned him the support of other ethnic groups. He is leading in every province, with the exception of Central and Eastern - the strongholds of Kibaki and Musyoka, respectively.

Mr. Kibaki says he supports more limited political devolution, and says Odinga's calls for decentralization risk exacerbating ethnic tensions.

Kenya's younger generations are also often seen as more favorable to Raila Odinga. Ngunyi says he represents a generation shift in Kenyan politics.

"He is fighting a generational war. He is effecting a generational succession. Rwanda, Uganda, Burundi, the republics around us have gone through their generational succession where the independence generation has been kicked out of power. What is happening in Kenya now, Raila is also effecting some kind of generational change," says Ngunyi.

If elected, Mr. Odinga would be the first president that was not a political leader at the time of independence.