The most important election for governor in decades is less than two months away. It comes at a time of rapid economic, demographic and social change in Minnesota. A wrong move now in state policy could erode the prosperity that several generations sacrificed to achieve.

It's too soon for us to recommend one candidate for governor. Campaigns matter, and we want this one to play out well into October before we make our endorsement.

But after watching a full month of general-election campaigning, we're issuing a challenge to moderate Minnesota voters seeking a break from polarization. A genuine three-way race is on. Independence Party candidate Tom Horner ranks as a serious contender, and he deserves full consideration by Minnesotans who in more ordinary times might not look at a third-party candidate. That's especially true of those who value a more centrist, pragmatic approach to governing than has so far been offered up by the GOP and DFL candidates.

This isn't a typical year in Minnesota politics. And it isn't typical of this newspaper to put an editorial on the Opinion Exchange section cover. But extraordinary times warrant a break with usual patterns.

Two developments since the Aug. 10 primary have earned Horner consideration alongside DFLer Mark Dayton and Republican Tom Emmer, despite the comparatively small size of his party.

The first is Horner's release of a well-crafted, credible answer to the giant question urgently confronting the next governor: How will you balance the state budget?

A deficit projected at $5.8 billion, or 15 percent of the cost of current state commitments in 2012-13, demands a swift gubernatorial response next year.

Among the three candidates, Horner's budget plan is the most detailed and sensible to date. It relies on new revenues (from both income and sales taxes) and spending restraint to close the gap. It also outlines reform measures on both the tax and spending sides of the ledger that would mitigate the negative impact of higher taxes on the economy, and of reduced spending on the reach and quality of government services.

The centerpiece of Horner's tax plan -- expansion of the sales tax to clothing and enough personal services to allow for a reduction in the sales tax rate -- is something this newspaper has backed for almost 20 years.

The second recent development pertains to a more political question: Can he win? Since Aug. 10, Horner's campaign has ramped up dramatically. His fundraising tally has jumped 45 percent in the past two weeks over the previous two-week period, giving him a greater ability to buy ads on TV. That's an impressive early showing for a third-party candidate.

The ability to advertise statewide on television is no guarantee of electoral success. But without it, a third-party candidate is sure to be relegated to also-ran or spoiler status. Horner now appears poised to move beyond that standing and to be seen along with Dayton and Emmer as someone who could conceivably be elected.

Horner's next challenge is to convince independent-minded voters that their votes won't be wasted, or that a strong Horner showing won't boost their least-favorite candidate. Those voters should know, judging from polling to date, that it's not clear whether DFLer Dayton or Republican Emmer would be more disadvantaged by a strong Horner showing.

They should also consider the opportunity the Horner candidacy offers them to take a stand against the ideological inflexibility afflicting both big political parties in recent years, in Minnesota and the nation. Horner is inviting Minnesotans to simultaneously reject both the specter of class warfare on one hand and antigovernment dogma on the other.

We're still watching. We believe Emmer is months overdue in explaining how he would miraculously erase the deficit while cutting taxes. We're hoping for more clarity from Dayton on how many Minnesotans would be affected by his proposed income tax increase, what their tax rate would be, and how much new revenue it would raise for the state. Independent analysts say that the new tax bracket and rate he's promoting won't generate the $4 billion he has said he wants to raise.

At this stage it appears that both Emmer and Dayton are committed to lopsided approaches that carry risks. Emmer seems to underestimate the harm that further deep spending cuts could do to Minnesota's social safety net and public services. Dayton doesn't fully appreciate the danger that sharp, narrowly targeted tax hikes could discourage investment and harm business.

We want more evidence from all three candidates that they possess the leadership traits that the times require. To succeed, the next governor must be a risk-taker and consensus-builder. That's a rare combination. Leadership skills, experience and temperament matter in the governor's office.

It's fortuitous that this crucial governor's race is marking time to a new political calendar. If this were a traditional year, today's editorial would be exhorting Minnesotans to go to the polls Tuesday and vote in the major-party primary of their choice. Only seven weeks would then remain for voters to compare the candidates before the Nov. 2 election.

The Aug. 10 primary made it possible for Minnesotans to take up that task in earnest four weeks ago. Some may still consider politics something that can wait until the days or even hours before the election, or may think they are justified in cursory, habit-bound consideration of the candidates. To them, we reiterate: Extraordinary times warrant a break with usual patterns. This year's gubernatorial election should summon Minnesotans to exercise their best citizenship. If they want to break from Minnesota politics as usual, Tom Horner is an increasingly credible alternative.