With the Vikings lease up after the 2011 season, Minnesota's new governor will play a critical role in rallying support for a new, nearly $1 billion stadium built largely with taxpayer dollars.

To his credit, the gubernatorial candidate whose public-affairs firm counts the professional football team as a client has been upfront about these business ties. From the beginning of his campaign, Tom Horner has disclosed the relationship, even as he says that "keeping the Vikings likely will require some public subsidy."

Minnesota voters deserve full disclosure of potential conflicts from all candidates before they go to the polls this November. In knowing who might have the ear of the governor, it's important to know who has had it in the past and how any potential conflicts of interest would be managed. That's why it's troubling that Horner, the Independence Party's endorsed candidate, has repeatedly declined to provide a comprehensive list of work his firm has done for other special-interest groups, businesses and various levels of Minnesota government. If he wants to be considered a serious candidate for state's most powerful office, Horner needs to act like one.

Read Horner's full response

Even as he's called for state politicians to have "honest conversations" with voters, Horner has sidestepped requests for a client list from Himle Horner. On May 20, he declined an Independence Party challenger's request to release the names of his clients. On Friday, Horner provided this response to an editorial writer's query: "... I've never had a citizen question on Himle Horner's client list. That issue comes mainly from other politicians and their allied special-interest groups who don't have anything to say about Minnesota's future or won't offer specifics on their vision."

Horner also cited client confidentiality, which is a fair concern. At the same time, Himle Horner appears to be more reticent than many similar firms about client disclosure. The Twin Cities firm Padilla Speer Beardsley, for example, provides an extensive list of clients on its website. Himle Horner does not, but does list its community involvement.

A search of online and Star Tribune databases and other resources reveals these past or current Himle Horner clients: Blue Cross and Blue Shield, the Mayo Clinic, Target, Northstar Commuter Rail, ClearWay Minnesota (an antitobacco group), PhRMA (drug manufacturers), Twin Cities hospitals, the Metropolitan Sports Facilities Commission, and Canterbury Park, which seeks a racino, another project that Horner supports. The search also turns up more than $3 million in Himle Horner public contracts over the past decade for clients such as ClearWay's predecessor, the Northstar Corridor project, the Minnesota Department of Transportation, Hennepin County, Dakota County, Anoka County, the city of Ramsey and the Transit Improvement Board. Some might argue that hiring outside consultants such as Himle Horner is unnecessary during an era of massive budget deficits. How will a Gov. Horner react if this type of work gets chopped?

Horner argues that he's being held to a higher standard than other candidates. But because of his firm's success, Horner's potential conflicts are more extensive than those of other candidates. Unlike others in the race, he also doesn't have a voting record.

On Friday, Horner said in a statement that if he wins, he will "sell all my shares in Himle Horner and would have no further financial interest or involvement with the firm." That's an important and welcome step, but he also should disclose the clients the firm has worked with that are not covered by confidentiality agreements.

Long before he ran for governor, Horner acknowledged that conflicts crop up when someone in a leadership role straddles the public and private sectors. On July 25, 2005, the Star Tribune ran a story detailing how a high-ranking member of the Metropolitan Council benefited from a $200,000 government consulting contract awarded to the Ramsey County Rail Authority, which then hired the Met Council member's law firm as a consultant.

One of the losing bidders for that consulting contract was Himle Horner. Horner at the time told reporters his firm wouldn't have bid for the contract if one of its principal officers was on the Met Council. "When we go into public service, we acknowledge that it is going to close the doors to some business," Horner said. It was exactly the right thing to say. Five years later, disclosing his firm's clients is the right thing to do.