Hacker was an academic political researcher, polytechnic lecturer, and editor of a newspaper, Reform, and entered Parliament circa 1961. He continued with at least some of these jobs while holding the office of Member of Parliament for Birmingham East.
For the first twenty years of his political career, Hacker was a member of the Opposition, and he served as Shadow Minister of Agriculture from 1974 on. In 1980, he served as the head of the unsuccessful party leadership campaign of Martin Walker; the winner of this campaign, Herbert Attwell, later went on to win the general election in 1981, and thereby became the UK's new prime minister. Hacker was nervous that Attwell would pass him over for a Cabinet post as an act of revenge for running Walker's campaign against him, but Attwell appointed Hacker to the cabinet as minister for the (fictitious) Department of Administrative Affairs. At least one news commentator of the time speculated that the appointment was actually an act of revenge, as the DAA had a reputation as "a political graveyard" that could end Hacker's career.
In Yes Minister, Hacker is joined by the ministry's Permanent Secretary, Sir Humphrey Appleby, who as a senior civil servant tries to control the ministry and the minister himself, and also by his Principal Private Secretary, Bernard Woolley. Hacker received his degree, a third, from the London School of Economics, and is frequently derided for this by the Oxford-educated Sir Humphrey. He and his wife, Annie, have one daughter, Lucy, a sociology student at the University of Sussex who plays a major role in the first series episode "The Right to Know".
Hacker gains an honorary doctorate from Baillie College, Oxford (a possible reference to Balliol College), in the second series episode "Doing the Honours". During the Christmas special episode, "Party Games", he is Party Chair, which gives him the opportunity — with the help of Sir Humphrey and other civil servants acting in their own interests — to become Prime Minister in an episode broadcast in 1985 (but according to the book adaptation, set in 1984).
Yes, Prime Minister follows on from this, with Hacker and Sir Humphrey raised to the highest levels in British government: Prime Minister and Cabinet Secretary respectively. Bernard remains Hacker's principal private secretary throughout.
An obituary for Hacker, written by his creators, Antony Jay and Jonathan Lynn, appears in Politico's Book of the Dead. The entry gives Hacker the same dates of birth and death as Paul Eddington, the actor who portrayed him. (These dates make Hacker 53 at the time of broadcast of the episode "Open Government") Although the series itself ends with Hacker still Prime Minister, this obituary mentions his later career as a member of the House of Lords. After his death, a college is named after him (Hacker College, Oxford).
Jim Hacker first appears in Yes Minister having been recently re-elected as Member of Parliament for Birmingham East, soundly defeating his opponents. His early character is that of a very gung-ho, albeit naive, politician, ready to bring sweeping change into his department, unaware that Sir Humphrey and the civil service are out to stop any semblance of change, despite their insistence that they are his allies. Hacker is also noted as having challenged Humphrey while he was a member of the Opposition by asking difficult questions when Sir Humphrey was testifying to a Parliamentary committee: Sir Humphrey stated that Hacker had asked "...all the questions I hoped nobody would ask," showing his new Minister to be at least a reasonably capable politician.
Before long, Hacker begins to notice that the Civil Service has been preventing any of his changes from actually being put into practice. Bernard is sympathetic to Hacker's plight and tries to enlighten his Minister as to the tricks and techniques employed by government staff, but his ability to help is limited by his own loyalties in the Civil Service. Hacker soon learns and becomes more sly and cynical, using some of these ploys himself. While Sir Humphrey nearly always gets the upper hand, Hacker now and again plays a trump card, and on even fewer occasions, the two of them work towards a common goal.
Hacker also learns that his efforts to change the government or Britain are all really for naught, as he discovers in the episode "The Whisky Priest", when he attempts to stop the export of British-made munitions to Italian terrorists.
Throughout Yes Minister, there are many occasions when Hacker is portrayed as a publicity-mad bungler, incapable of making a firm decision, and prone to blunders that embarrass him or his party, eliciting bad press and stern lectures from the party apparatus, particularly the Chief Whip. He is continually concerned with what the newspapers of the day will have to say about him, and is always hoping to be promoted by the Prime Minister. (Hacker ran the unsuccessful campaign for a political ally during the party's last leadership election - his man lost, becoming Foreign Secretary, and leaving Hacker nervous about his prospects under the winner, now Prime Minister.) He is equally afraid of either staying at his current level of Cabinet seniority, or being demoted.
Just prior to the start of Yes, Prime Minister, Hacker shows a zeal for making speeches and presents himself as a viable party leader after the Prime Minister announces his resignation in the episode "Party Games". He is given embarrassing information about the two front-runner candidates, and manages to persuade them (by insinuating that secret information pertaining to both may be revealed to the public) to drop out of the race, and lend their support to him. With help from the recently promoted Sir Humphrey and other senior civil servants, Hacker emerges as a compromise candidate and becomes head of his party unopposed - and Prime Minister.
In Yes, Prime Minister Hacker strives to perfect all the skills needed by a statesman, giving more grandiose speeches, dreaming up "courageous" political programmes, and honing his diplomatic craft, nearly all of these attempts landing him in trouble at some point.
In a Radio Times interview to promote the latter series, Paul Eddington stated, "He's beginning to find his feet as a man of power, and he's begun to confound those who thought they'd be able to manipulate him out of hand."
Hacker becomes a more competent politician by the end. Though primarily interested in his personal career survival and advancement, he, unlike Sir Humphrey, views government as a means rather than an end in itself.
Hacker has many prominent habits that feature throughout the series:Drinking. Hacker enjoys various alcoholic beverages, particularly harder liquors, including Scotch whisky: "the odd drinkie", as he likes to call them. He is seen drunk on more than one occasion and was caught drinking and driving in the episode "Party Games". He used his political immunity to escape charges.
Disdain for certain types of culture. Sir Humphrey thinks Hacker to be a cultural philistine who is unaware of the importance of protecting Britain's artistic heritage. Hacker believes it only important to the upper-class snobs (such as Humphrey himself), and several other "wet, long-haired, scruffy art lovers", arguing that operas created by Italians and Germans are not representative of Britain's cultural heritage. However, upon becoming Minister for the Arts (in "The Middle-Class Rip-Off"), Hacker asks Humphrey if he could tag along on a gala night at the Royal Opera House. Humphrey is delighted by the volte-face and declares, "Yes, Minister" enthusiastically. But Hacker and his wife enjoy seeing foreign films, and in the same episode Hacker demonstrates some grasp of art, enough to make a strong case that a disputed art gallery in his constituency is not worth saving. (See also "Football" below.)
Pomposity. Hacker is often seen going off into sentimental, overly pretentious speeches either to himself or to Bernard and Sir Humphrey, holding his lapel on his suit jacket in a very royal manner. He also mimicked Napoleon by slipping his hand in the front of his suit jacket upon hearing he was selected by the party to become party leader and hence Prime Minister. However, it appears that Hacker's political idol is Winston Churchill: he occasionally speaks in the statesman's gruff style, on several occasions imitating or paraphrasing Churchill's "We shall fight on the beaches" speech, and is seen reading biographies of him.
Football. Hacker believes that sport is of a greater cultural importance and is even willing to sacrifice a local art gallery in order to bail out his constituency's football team, the fictional Aston Wanderers, that was being threatened with bankruptcy. He didn't support the team though, and was mentioned as being an Aston Villa supporter in the first episode.
Hacker's political party is never explicitly stated - a deliberate ploy by the series' creators to prevent the show from having a partisan affiliation. This begins in very first scene of the 'Yes Minister' pilot episode, where the victorious Hacker's party rosette is white, as opposed to the red (for Labour) and blue (for the Conservatives) rosettes worn by the other candidates. The Labour and Conservative parties are eventually compared in The National Education Service, when Sir Humphrey tells Bernard, "When there is a Labour government, the education authorities tell them that comprehensives abolish the class system and when there's a Tory government we tell them that it's the cheapest way of providing mass education; to Labour we explain that selective education is divisive and to the Tories we explain that it is expensive." but Sir Humphrey then goes on to tell Hacker neither of these things, forgoing any suggestion that Hacker is from either party. Throughout the show, Hacker's political opinions tend towards reform of administration and are neither left nor right wing. However, the concentration on "making budget cuts (of 5%)" in the Yes Minister episode "Doing the Honours" and cutting taxes in the Yes Prime Minister episode "The Smoke Screen" allude towards him being a conservative; and the writers have since established that they privately saw Hacker as a centrist "wet" Conservative.
In a radio broadcast spoof of Yes Minister performed by both Eddington and Nigel Hawthorne, both of whom played their respective parts from the show, Hacker is a Minister in the government of the day, that of Margaret Thatcher, who also played herself as Prime Minister. In the sketch, she asks that Hacker and Sir Humphrey abolish economists.
In the 2010 stage production of Yes, Prime Minister, the role was played by David Haig.