Cline received a Bachelor of Arts degree in Political Science from the University of Saskatchewan in 1976. He campaigned for the NDP while still a student, finishing third in Regina South in the 1975 provincial election. He subsequently received a Bachelor of Laws from the University of Saskatchewan, was called to the Saskatchewan Bar in 1980, and was a partner in the Saskatoon firm Woloshyn & Co. prior to his 1991 election (Calgary Herald, 9 January 1996).
He was first elected to the Saskatchewan legislature in the 1991 provincial election, winning election in the safe NDP seat of Saskatoon Idylwyld. The New Democrats won a majority government under the leadership of Roy Romanow, and Cline served as a government backbencher. He was re-elected for the new seat of Saskatoon Mount Royal in the 1995 election.
In March 1995, Cline announced that he would support his local Member of Parliament, Chris Axworthy, for leader of the federal New Democratic Party (Globe and Mail, 23 March 1995). Axworthy subsequently declined to run.
Cline was called to cabinet on November 22, 1995, and was given the senior portfolio of Minister of Health. He continued with the Romanow government's previous health reforms, and defended the decision to create consolidated regional health boards (Saskatoon Star-Phoenix, 25 November 1996). A defender of the public health system, he helped bring forward the Health Facilities Licensing Act in May 1996 to restrict private clinics from being established in the province (Saskatoon Star-Phoenix, 2 May 1996). Shortly thereafter, he eased restrictions on private nursing homes in the province (SSP, 14 May 1996). Cline described this as a fair compromise, though some in the public sector described the latter initiative as an abandonment of medicare (SSP, 24 May 1996).
During the same legislative session, Cline introduced legislation to permit greater tax incentives for those who donate money to the health-care system (SSP, 22 May 1996). In August 1996, he announced that the provincial and federal governments would cooperate to construct a new Athabasca health facility in northern Saskatchewan (SSP, 14 August 1996). Later in the year, after accusations of underfunding by the Saskatchewan Nurses Union, Cline and the Romanow government introduced an additional $40 million for the provincial health system (SSP, 22 August 1996).
In 1997, Cline indicated that Saskatchewan would take steps toward the legalization and regulation of midwifery, (Globe and Mail, 27 March 1997) and announced a $25,000 incentive for doctors setting up a practice in rural communities (Winnipeg Free Press, 26 April 1997). He also spoke out against plans by the federal government of Jean Chrétien to offer pharmaceutical companies twenty-year patent protection for new prescription drugs (SSP, 17 April 1997). In June 1997, he encouraged the Canadian federal and provincial governments to pool their resources in a class action lawsuit against tobacco companies for health-related expenses (18 June 1997)
He also served as Acting Minister of Labour from July 1, 1996 to August 6, 1996.
Cline was promoted to Minister of Finance in the Romanow government on June 27, 1997, replacing Janice MacKinnon. He introduced the Romanow government's fourth consecutive balanced budget in March 1998. Highlighted by an unexpected 2% provincial income tax cut, the budget also provided tax incentives for the film and energy sectors, while increasing spending on health, education and roads (Financial Post, 20 March 1998). In August, he released figures indicating that the provincial surplus target was $11 million more than expected (Globe and Mail, 28 August 1998).
Cline wrote an editorial piece in the Financial Post newspaper in mid-1998, arguing that the Romanow government had prevented Saskatchewan from falling into bankruptcy through its policy decisions since 1991 (4 August 1998). The editorial was a response to a previous Post article which questioned the Romanow government's financial record.
Just before the 1999 budget was unveiled, Cline announced that the Saskatchewan government would contribute $140 million to a farm-aid package. This payment reduced the estimated budget surplus to $8 million from $105 million (Times-Colonist, 2 March 1999). The final totals indicated a surplus of $28 million (Saskatoon Star-Phoenix, 29 October 1999).
Cline's 1999 budget reduced the provincial sales tax by 1%, and put $195 million of new spending into health care (Winnipeg Free Press, 27 March 1999). Two months later, he announced that the province would conduct a review of its tax system (Globe and Mail, 7 May 1999). This announcement led to the creation of the Personal Income Tax Review Committee, which held several public meetings throughout the summer of 1999, and recommended a new personal income tax system for Saskatchewan, which Cline introduced in the 2000 Saskatchewan budget.
The NDP was unexpectedly reduced to a minority government in the 1999 provincial election, and later formed a coalition government with the Liberal Party. Cline was personally re-elected without difficulty and was retained as Finance Minister.
Cline released the coalition government's first budget in 2000, which featured income tax cuts and an expansion of the sales tax. He described the budget as providing for "growth and opportunity for Saskatchewan" rather than "buying the short-term goodwill of people with their own tax dollars" (Globe and Mail, 30 March 2000). It was largely welcomed by the business community, and was given an "A" grade from the leader of the North Saskatoon Business Association (SSP, 30 March 2000). The budget also included a controversial provision to extend the provincial sales tax to off-reserve aboriginals (Globe and Mail, 17 April 2000).
Expanding oil and gas revenues brought the Saskatchewan government an unexpected windfall of $370 million in late 2000. In late November, Cline was able to announce $150 million worth of spending for road and highway repairs over the next three years (Canadian Press, 30 November 2000). The final budget surplus for the fiscal year ending in 2001 was $58 million, much higher than the $9 million projected (Broadcast News, 20 July 2001).
Romanow announced his retirement as Premier of Saskatchewan and NDP leader in September 2000. Cline was mentioned by some as a possible successor (Canadian Press, 25 September 2000), but he declined to contest the position and did not publicly endorse another candidate (SSP, 1 December 2000). Lorne Calvert was chosen as Romanow's successor in February 2001, and he retained Cline as Finance Minister.
Cline's first budget under Calvert introduced $370 worth of new spending, while also providing tax cuts for small business and projecting a narrow $2.8 million surplus. Some have argued that the budget marked a turning away from the more fiscally conservative approach of the Romanow government (Canadian Press, 30 March 2001). Subsequent declines in gas revenue and losses in federal equalization later forced Cline to withdraw $479 million from the fiscal stabilization fund to prevent a return to deficit spending (Canadian Press, 20 February 2002). In early 2002, he announced that the province would begin issuing quarterly financial reports (Broadcast News, 18 February 2002).
Despite the worsening economic circumstances, Cline was able to present the NDP's eighth consecutive balanced budget in early 2002 with a modest surplus of $45,000 (Regina Leader-Post, 28 March 2002). The budget reduced the size of government, while further increasing health spending and introducing taxes on tobacco and liquor. To avoid going into deficit, Cline was required to withdraw another $225 million from the fiscal stabilization fund (Reuters News, 28 March 2002). A subsequent Prairie drought reduced revenues further, and he needed to access the fund again later in the year (National Post, 28 November 2002). In December 2002, Cline and his government reduced fees and taxes in the oil industry to encourage further provincial development (Reuters News, 16 December 2003).
Cline endorsed Lorne Nystrom for the leadership of the federal New Democratic Party in September 2002, and was part of Nystrom's campaign team (Canadian Press, 19 September 2002). At the party's 2003 convention, Cline argued that Nystrom was best positioned to "speak to the realities of the market economy and how to generate wealth" while also affirming the role of public programs "to maximize equality of opportunity" (Canadian Press, 22 January 2003). Nystrom finished third against Jack Layton.
Cline's third-quarter update in January 2003 showed a surplus of $100,000, maintained by the stabilization fund. While acknowledging the surplus, the auditor general suggested that the government was concealing some economic difficulties by transferring funds among departments and crown corporations (Canadian Press, 30 January 2003).
After serving as Finance Minister for over five years, Cline was reassigned as Minister of Justice and Attorney-General and as Minister of Industry in February 2003. He replaced the retiring Chris Axworthy in the former position, and Eldon Laudermilch in the latter. Jim Melenchuk was chosen as Cline's successor in Finance.
Cline announced in late February 2003 that the province would hold an inquiry into the death of Neil Stonechild, a seventeen-year-old aboriginal youth who was found frozen to death in 1990. His death was ruled accidental, but many believe he was abandoned outside of town by members of the police force. Both the Federation of Saskatchewan Indian Nations and the Saskatoon Police Association welcomed the decision for an inquiry (Canadian Press, 20 February 2003).
Cline also announced that Saskatchewan would become the first province to completely protect Registered Retirement Savings Plans (RRSPs) and related funds from creditors, in the event of bankruptcy (Canadian Press, 25 February 2003).
In June 2003, Cline announced that the Saskatchewan government would charge David Ahenakew with promoting hatred. Ahenakew, once a respected aboriginal leader, had delivered a speech describing Jews as a "disease" who deserved to be "fried" in The Holocaust. The Canadian Jewish Congress commended Cline for his courage in bringing the case before the courts (Globe and Mail, 12 June 2003).
In October 2003, Cline announced that the Saskatchewan government would establish a commission to investigate the wrongful conviction of David Milgaard in 1969 (Kitchener-Waterloo Record, 1 October 2003).
In June 2003, Cline led a Saskatchewan trade delegation to an international conference on biotechnology in Washington, D.C. His intent was to develop international contacts, and specifically to export Saskatchewan's biotechnology expertise to India (Broadcast News, 17 June 2003). The initiative was reported as a success (Saskatchewan Business, 1 September 2003).
The NDP narrowly recovered their majority government in the 2003 provincial election. Cline, once again re-elected without difficulty, was appointed to a restructured Ministry of Industry and Resources while yielding the Justice portfolio. He also became Chair of the Liquor and Gaming Authority, and minister responsible for the Saskatchewan Research Council, Saskatchewan Opportunities Corporation, Tourism Saskatchewan, Information Services Corporation of Saskatchewan, and Investment Saskatchewan (formerly known as Crown Investments Corp.). In December 2003, he announced that Titanium Corporation Inc. would construct the world's first Mineral Sands Processing Facility at the Regina Research Park (Market News Publishing, 12 December 2003).
As chair of the Liquor and Gaming Authority, Cline approved plans for a new casino on the Whitecap Dakota Sioux reserve in August 2004. The provincial auditor general had previously raised concerns about the Saskatchewan Indian Gaming Authority's accounting methods. Cline acknowledged that the SIGA had made significant improvements in recent years, and indicated that the government would hold the casino's profits in trust if further concerns were not resolved (Canadian Press, 7 August 2004).
Cline led a twelve-day business excursion to Europe in September 2004, and spoke at the World Nuclear Association Symposium in London (Broadcast News, 3 September 2004). He presented to the conference on Saskatchewan's pioneering Reclaimed Industrial Sites Act, which requires funds to be in place to ensure environmental reclamation and monitoting after mines shut down. In response to opposition questions later in the year, he argued that constructing a nuclear power plant in Saskatchewan would not be economically viable (Canadian Press, 19 October 2004).
In January 2005, Cline presided over an economic conference in Saskatoon billed as the Centennial Summit. Representatives from several industries gathered in the city, and called for a more competitive business environment (Saskatchewan Business, 1 March 2005). The following year, Calvert and Cline headed a Saskatchewan delegation on energy resources to the United States, which met with Vice-President Dick Cheney (The Oil Daily, 22 February 2006).
Cline was identified as the best minister in the Calvert government in 2005 by members of the government, opposition and media, amid a general economic recovery in the province (Regina Leader-Post, 18 June 2005). He relinquished cabinet responsibility for the Gaming and Liquor commission in early 2006 (SSP, 4 February 2006).
On December 15, 2006, Cline announced that he would not be seeking re-election. On April 19, 2007, the Saskatchewan New Democrats in the constituency of Saskatoon Massey Place selected Cam Broten to be the candidate in the next provincial election. Broten won the nomination on the first ballot after a three-way race. 400 people were in attendance at the nomination meeting. On April 23, 2007, Cline stated the following about Broten:
"Cam Broten is young, enthusiastic, intelligent, hard-working, and absolutely dedicated to the ideas and values at the heart of Saskatchewan’s success ... I have every confidence that he will prove to be an outstanding representative for Saskatoon Massey Place." (Saskatchewan Hansard, April 23, 2007, p. 1363)
After leaving politics, Cline returned to work in the private sector in Saskatoon, first as a Vice Presiodent of a diamond exploration company for 4 years and, beginning in 2012, as a corporate lawyer for a potash company, of which he became a Vice President later that year. He remains active in the community, serving on various community and industry boards, all in a voluntary unpaid capacity.
In 2008, a memoir of his time in politics, Making a Difference—Reflections From Political Life, was published (Thistledown Press, Saskatoon) and Cline oversaw the construction of a new home in Saskatoon that year and in 2009.