It’s an easy call on Nov. 6: Vote for a higher cigarette tax, and Missourians will benefit mightily.

So why do gubernatorial candidates Jay Nixon and Dave Spence have such backward positions on the issue?

I’ll get to that in a minute, but let’s start with the positives of Proposition B.

Hiking the rock-bottom, lowest-in-the-nation tax from 17 cents a pack to 90 cents would generate from $300 million to $400 million a year. The tax would:

• Reduce teen smoking rates by making cigarettes more costly. Stopping thousands of young people from taking up the harmful habit would be a substantial long-term victory.

• Raise new revenue to improve K-12 schools and higher education. A total of 80 percent of the new funds would go for those causes. School districts in the Kansas City area would get millions of dollars, which they could use to replace teachers and educational programs slashed during the recession, all without imposing higher property taxes on residents.

• Support programs aimed at helping more people quit smoking. Proponents estimate up to 33,000 adults would snuff out their cigarettes for good.

• Cut the potential for future health-related problems of smokers. That would trim the demands on taxpayer funding for Medicaid and other programs that now pay for health care of people who suffer from medical problems because of their harmful habit. Overall, tax supporters point to more than $1 billion in potential savings on health care costs.

Kudos to U.S. Sen. Claire McCaskill for backing the cigarette tax increase, even though the stance might cost her a few votes with rural Missourians. Attorney General Chris Koster deserves the same pat on the back for being an early advocate for the increase, even while he’s also up for re-election.

But don’t look for leadership on this issue from Nixon or Spence.

The refusal by Gov. Nixon, a Democrat, to endorse the tax is politically cowardly and nearly inexplicable.

Polls have long showed that Nixon probably will cruise to re-election against Spence, a Republican. So even for a Democrat who’s often seen as being more of a Republican on fiscal issues, Nixon could have supported the cigarette tax without much voter backlash.

The tax isn’t on the general population; it’s targeted at smokers.

And because much of the extra funds will flow to K-12 schools and higher education, Missouri would be investing tens of million in priorities that Nixon has always claimed are high priorities.

With his muteness on the tax, however, Nixon essentially is coming out against creating more revenue to improve education in the state.

As for Spence, it’s true that he’s taking the usual GOP, anti-tax stance. But his reasoning is odd and financially flawed.

In a recent interview with The Star’s editorial board, Spence said he had “looked into the faces” of Missourians and determined that they couldn’t afford a few dollars a year in higher taxes.

What rubbish. It’s a good thing Spence probably won’t be governor in a few years, which is when he would look into the faces of Missouri smokers when they have gotten a terrible disease and are having to fork over tens of thousands of dollars for the health care needed to save their lives. If they can even save their lives by that point.

Now, a more upbeat ending.

It’s true that Missouri voters twice in the last decade have narrowly rejected cigarette tax hikes. This time around, though, the opposition is quieter because big cigarette companies aren’t financing a get-out-the-vote campaign.

Plus, even the new 90-cent tax per pack would be far lower than the national average of around $1.50 a pack. Missouri is hardly going to be an outlier on this issue.

Opponents led by convenience-store operators, who say the higher tax means they will sell fewer cigarettes, especially in the Kansas City area.

That’s bad news for them. But it would be an excellent outcome for most Missourians.