Umesh Kushwaha represents the
Mahnar constituency of the Bihar, which came into existence once again after the delimitation exercise of 2008. In 1957, Banarasi Devi a candidate from
Indian National Congress represented this constituency but after its revival in 2008 the seat has been a stronghold of
National Democratic Alliance. In 2010 Legislative Assembly Elections when
Janata Dal (United) was a member of
National Democratic Alliance, Dr. Achyutanand of
Bharatiya Janata Party contested and won the seat but he was defeated by Kushwaha in the 2015 Elections with a large difference of 27,000 votes. Kushwaha was then a candidate of
Mahagathbandhan (Grand Alliance) which included
Rashtriya Janata Dal and
Janata Dal (United). Later the Grand Alliance was broken due to differences between the two major political parties. In 2020 Assembly Election to Bihar Legislative Assembly JD(U) again made its candidate from the Mahnar seat. Umesh lost the 2020 Assembly elections to Veena Devi, the wife of RJD strongman
Rama Kishor Singh. The anti-incumbency situation in the state against ruling JD (U) and the step taken by
Chirag Paswan to weaken JD (U) by placing its candidates against it and not against BJP resulted in defeat of a large number of sitting MLAs of JD (U). In January 2021, Kushwaha was appointed to the post of Bihar state president of
Janata Dal (United) following the resignation of Bashishtha Narayan Singh on health grounds. The party's step was reported to be a part of the strategy to revive its decaying old socio-political coalition of Koeri and Kurmi caste, which needed revival after the poor performance of JD(U) in Bihar Assembly election 2020. In the year 2025, JDU fielded him as its candidate for the Bihar Legislative Assembly elections from
Mahnar Assembly constituency. In the tough contest, he defeated Ravindra Singh of
Rashtriya Janata Dal with over 38000 votes. This made him second term MLA from Mahnar Assembly constituency. ==Controversies==