[citation needed] He was elected to the Legislative Assembly of Saskatchewan as the Member (MLA) for the constituency of Moose Jaw South, serving in the Official Opposition to Grant Devine's Progressive Conservative government.

[7] Calvert joined the race, alongside former NDP MP and then-provincial justice minister Chris Axworthy, three sitting cabinet ministers in Buckley Belanger, Joanne Crofford, and Maynard Sonntag, former National Farmers Union president Nettie Wiebe, and former Young New Democrats president Scott Banda.

[12][13] During his full term in office, Calvert expanded child care spaces and introduced a number of targeted welfare programs.

[14] Calvert's spending plans were buoyed by a renewed boom in commodity prices, which led to significant increases in resource revenue for the province.

[18] Late in the term, Calvert became increasingly antagonistic with the federal government, a minority parliament led by Stephen Harper's Conservatives.

In March 2007, Calvert argued that the clawback of non-renewable resource revenues from the equalization formula as implemented in the 2007 federal budget would leave Saskatchewan getting significantly less than had been promised.

[20] Calvert and his government were defeated in the 2007 provincial election, in which management of the province's booming economy and health care became focal points.

[18] Importantly, unlike Hermanson, new Saskatchewan Party leader Brad Wall made a vocal commitment not to privatize the province's crown corporations.

[26] Dwain Lingenfelter, a former cabinet minister in the government's of Romanow and Allan Blakeney, was elected the party's new leader in a four-person contest on June 6, 2009.

[27] At the end of the Spring session in May 2009, Calvert touted the economic progress his government had made, and revealed that he planned to return to the United Church.

B'nai Brith Canada stated that the cartoon "trivializes the crimes of the Holocaust and causes undeserved anguish to those who survived that evil regime".