A shift in Kenyan demographics has taken place since then, with the Luo and Luhya tribes from the West of Kenya being the primary sources of internal emigration. By 1995 Kibera had become a predominantly Luo slum and Mathare Valley nearby the predominantly Kikuyu slum area. The coincident rise of multi party politics in Kenya has caused the Luo leader and MP for much of Kibera, the parliamentary seat of Langata, Raila Odinga to be known for his ability to bring out a formidable demonstration force instantly. Meanwhile, Mathare Valley has become a hotbed of gang warfare. Political tensions in the nation between the ethnic tribes escalated after the re-election of President Kibaki in 2007.