[2] Karua ran for presidency in 2013 under the Narc-Kenya ticket making her the third woman to run for the highest office, after Charity Ngilu and Wangari Maathai in the 1997 elections.
[6] After graduating, from 1981 to 1987 Karua worked as a magistrate in various courts including those at Makadara, Nakuru and Kibera, receiving credit for careful discernment.
Cases included the treason trial of Koigi Wamwere and that of the Kenyan member of parliament Mirugi Kariuki.
[5] Karua was a member of the opposition political movements that successfully agitated for the re-introduction of multi-party democracy in Kenya in the early 1990s.
In September 1992, she walked out of the party nomination elections which she regarded as compromised leaving her sole opponent Geoffrey Karekia Kariithi to be declared winner.
[11] In 2001, when the Constitutional Review Bill was laid before the House, the entire Opposition with the exception of Karua walked out of Parliament.
The Bill had been rejected by the Opposition as well as Civil Society but Karua was of the view that as elected representatives, instead of walking out, it would be more prudent to remain in Parliament and put the objections on record.
[2][5] Karua remained Justice and Constitutional Affairs Minister in the Cabinet appointed by Kibaki on 8 January 2008, following the controversial December 2007 election.
[12] In an interview with BBC's HARDtalk in January 2008, Karua said, regarding the violent crisis that had developed over the election results, that while the government had anticipated that the opposition Orange Democratic Movement (ODM) of Raila Odinga might be "planning mayhem if they lost", it was surprised by "the magnitude" of it, calling the violence "ethnic cleansing".
[13] Karua headed the government's team in negotiations with the opposition regarding the political dispute that resulted from the election.
In the grand coalition Cabinet that was announced on 13 April 2008, Karua remained in her post as Minister of Justice, National Cohesion and Constitutional Affairs.
There was virtually no competitive election during the party's national delegates' convention at the Bomas of Kenya in Nairobi as all the officials including Ms Karua were being endorsed.
[18] Martha Karua would make a come-back in Kenya's political scene in the 2017 general election seeking for a gubernatorial seat in Kirinyaga County.
[22] Karua later abandoned her political relationship with Raila and supported Jubilee Party ahead of the 2017 Kenyan general election.
[23] In December 2015 Karua admitted to receiving a Ksh 2 million donation to her presidential campaign costs from British American Tobacco.