Ansari began his political career as a member of the Bahujan Samaj Party (BSP). In 1996, he was elected as an MLA from the Mau constituency for the first time. He went on to win the seat four more times, in 2002, 2007, 2012, and 2017, as a candidate of different political parties.

Ansari has been involved in several criminal cases over the years. He was accused of the murder of BJP MLA Krishnanand Rai in 2005 and was arrested in 2007. He spent several years in jail before being acquitted of the charges in 2019.

In 2019, Ansari joined the Bahujan Mukti Party (BMP), which was founded by his brother Afzal Ansari. He contested the 2019 Lok Sabha elections from the Ghazipur constituency but lost to the BJP candidate.

Ansari was later shifted to the Ropar jail in Punjab from the Banda jail in Uttar Pradesh, citing security concerns. He was then extradited to Uttar Pradesh in April 2021, where he is facing several criminal cases.

Despite his controversial past, Ansari has a significant influence in eastern Uttar Pradesh, especially in the Mau district. His supporters consider him a champion of the backward classes and a strong voice against the dominant upper-caste groups in the region.

In conclusion, Mukhtar Ansari is a prominent Indian politician with a tumultuous past. His political career has been marred by several criminal charges, but he remains a significant figure in the politics of eastern Uttar Pradesh.