Outside of politics, Lingenfelter has served on a variety of corporate and non-profit boards, and has directed CypressView Land, a farming and ranching business, since the 1990s.

Lingenfelter decided to run in the by-election to succeed Blakeney as MLA for Regina Elphinstone; he was successful, and re-joined the legislature in 1988 under new NDP leader Roy Romanow.

[6] After being re-elected in the 1991 election, which resulted in a large NDP majority, Lingenfelter returned to cabinet when he was named Minister of Economic Development.

[8] However, earlier in 2000, Lingenfelter announced that he would be resigning to pursue private sector opportunities, suggesting he would be taking work in the oil industry.

Romanow's successor, Lorne Calvert, announced his retirement in 2008, a year after losing the 2007 election to Brad Wall's Saskatchewan Party.

[12] He was joined in the race by former party president Yens Pedersen, MLA Deb Higgins, and doctor Ryan Meili.

Lingenfelter was considered the frontrunner, and by Spring 2009 had opened a wide lead in fundraising over his rivals ahead of the June 6 leadership election.

[13] However, Lingenfelter courted controversy when it was revealed that his campaign had signed up hundreds of new party members without their knowledge, and paid for 1,100 memberships.

[15] After the leadership vote, MLA Harry Van Mulligen resigned his Regina Douglas Park seat to allow Lingenfelter to run in a by-election there.

Polls ahead of the election suggested that Wall's Saskatchewan Party was heavily favoured to form another majority government, and the results bore this out.

[20] Lingenfelter later admitted that he felt "rusty and made lots of mistakes" during the campaign, but also that despite putting forward a good platform he did not expect to defeat what was a relatively new and popular Wall government.