[3] Due to the financial problems of his family, he was raised under his eldest brother, who was working in Masan (now under Changwon), South Gyeongsang during that time.

[5] After completing his national service, Jeon joined Haemaru Law Firm in 1993, where he met Roh Moo-hyun who later became the President of the Republic.

[3][4][5] He became a lawyer specialising labour issues, defending and helping foreign workers, industrial victims and so on.

[4] To overcome this crisis, Jeon had established a legal aid group to support Roh and became its assistant administrator.

[10] In 2004, the opposition MPs had voted 193 to 2 in favour of the impeachment of the President Roh, where the de facto ruling Uri Party was excluded.

[12] He then contested for Sangnok 1st constituency under the banner of the United Democratic Party (UDP), but was defeated by the GNP candidate Lee Hwa-soo.

[17] However, on 21 October, approximately 2 months before the election, he withdrew from the presidential campaign following the public backlash for being "too pro-Roh Moo-hyun".

[22][23] In the 2020 election, Jeon faced a challenge from the United Future Party (UFP) candidate Park Ju-won, the former Mayor of Ansan who contested under the banner of the now-defunct PP 4 years ago.

[28] Prior to the 2018 local elections, Jeon was widely considered as the potential candidate for Gyeonggi governorship.

[30] On 6 March, the same day when the South Chungcheong Governor Ahn Hee-jung had resigned over rape controversy, Jeon officially launched his bid for Gyeonggi governorship.

[32] Nevertheless, on 20 April, Jeon lost to the former Seongnam Mayor Lee Jae-myung, who had been the most favourable candidate for Gyeonggi governorship.

[33][34] Although Jeon conceded his defeat[35] and subsequently helped Lee to win, several pro-Moon Jae-in supporters did not accept the result; some even protested that they would rather vote the incumbent and the Liberty Korea Party (LKP) candidate Nam Kyung-pil.

[37] On 4 December 2020, Jeon was designated the new Minister of the Interior and Safety by the President Moon Jae-in, replacing the incumbent Chin Young.