Abang Johari's second great-grandfather was Datu Patinggi Haji Abdul Gapor, the former governor of Sarawak preceding James Brooke's era.

[15] At the same time, he aligned himself with Parti Pesaka Bumiputera Bersatu (PBB), a component of the ruling Barisan Nasional (BN) coalition at both federal and state levels.

Although initially reluctant to contest, Abang Johari declined an offer from Abdul Rahman Ya'kub, then Chief Minister, to run for the vacant seat.

[17] Following advice from his mother to respect the elders,[17] he eventually accepted the offer and won the seat in the by-election, marking his formal entry into the state legislative assembly.

[18] After retaining his seat in the 1987 state election, Abang Johari was promoted to a full ministerial position and joined the cabinet under Abdul Taib as the Minister of Industrial Development.

[18] In 2004, a cabinet reshuffle led to Abang Johari's appointment as Minister of Housing, a position he held while winning the 2006 state election.

[18] Abang Johari continued his political journey after winning his seat in the 2011 state election, once again becoming Minister of Tourism under Abdul Taib's leadership.

In the wake of Adenan's death, Abang Johari's name emerged as a potential successor, given his position as one of the ruling party's deputy presidents, alongside Douglas Uggah Embas and Awang Tengah Ali Hasan.

[29] Abang Johari assumed office as the successor to Adenan after being appointed by Governor Abdul Taib Mahmud on 13 January 2017.

[31][32] Following the mourning period, Abang Johari expressed his intention to maintain continuity by retaining much of the previous cabinet lineup from Adenan's administration.

One notable aspect of these efforts is the support extended to Chinese private schools, including the commitment to recognise the Unified Examinations Certificate (UEC)[35] and the allocation of financial assistance totaling RM10 million annually.

This includes the implementation of an international curriculum, which integrates English alongside Bahasa Melayu to equip students with global competencies.

[39] According to him, this initiative reflects a commitment to equitable access to higher education and underscores the government's dedication to investing in the future of Sarawak's youth.

[44] Under Abang Johari's leadership, the state government formed the Other Religious Affairs Unit (UNIFOR) in April 2017 to aid all religions and protect the interests and welfare of Sarawak's non-Muslims.

[49] Abang Johari has always reminded the non-Muslims in Sarawak that they are allowed to use the word "Allah" at any time,[50][51] saying that "it's not human beings who judge themselves as pious but it is God".

[62] The coalition focuses on Sarawak's interests and rights based on the Malaysia Agreement (MA63) and remain an opposition at the Pakatan Harapan (PH) federal government.

[61] On 23 August 2018, Abang Johari announced that GPS has been registered and is awaiting the issuance of the official letter from the Registrar of Societies.

[68][69] By mid-2021, the political crisis at the federal level had worsened when several MPs from UMNO, one of the components of Barisan Nasional, withdrew support for Muhyiddin.

[70][71][72] Even so, GPS under Abang Johari remained steadfast in its stance to continue supporting the Muhyiddin-led federal government,[73] saying that "now is not the time for politicking but rather for uniting to face the pandemic crisis".

One key initiative involves building more healthcare facilities in remote areas and expanding training programs for medical personnel to address shortages in these regions.

[80] In response, Abang Johari announced a two-week stay home order on everyone entering the state as part of measures to prevent the escalation of the disease.

[89] Sarawak has been praised by Director General of Health Noor Hisham Abdullah and become an example to other states in Malaysia for successfully curbing the spread of COVID-19.

[90] In response to the various impacts of COVID-19, more than RM5.6 billion was spent by the Abang Johari-led state government to implement a few aid packages to help the people affected by COVID-19 known as Bantuan Khas Sarawakku Sayang (BKSS).

[108][104] According to Abang Johari, the establishment GPS was inspired by the spirit sparked by his predecessor Adenan in fighting for the rights of Sarawak as enshrined in the Malaysia Agreement 1963 (MA63).

[125] Abang Johari also said that under the Item 2(c) of the State List, Ninth Schedule of the Federal Constitution, PETROS is able to exercise its rights on Sarawak waters.

[130] On 4 June 2018, PETRONAS filed a suit in the Federal Court of Malaysia in order to assert its position as the exclusive owner of Malaysian oil resources (including Sarawak) and the 1974 Petroleum Development Act is still valid.

[136] In September 2019, Prime Minister Mahathir Mohamad stated that payment of 20% oil royalty is not possible for Sabah and Sarawak because it may compromise financial status of PETRONAS.

Besides, both parties also agreed that the Petroleum Development Act 1974 is valid with PETRONAS as the sole regulator of oil and gas industry in Malaysia.

The election has seen the nomination of Abang Johari to contest the constituency seat of Gedong after its incumbent decided to not running for re-election.

After a state constitutional amendment was successfully passed on 15 February 2022, Abang Johari's position as Chief Minister was changed to Premier.