If taxes are one of life’s certainties, then nothing is more guaranteed than the Idaho property tax devoted to public schools.

Every year, the amount patrons voluntarily shoulder to boost their children’s education goes up — in good years and bad.

As Idaho Education News’ Kevin Richert reported last week, the state set another record: The amount of money 92 of Idaho’s 115 school districts raised from supplemental property tax levies reached $216.6 million. That’s the fifth consecutive increase — or $36.4 million since the 2014-15 school year.

Among the major recipients:

l Coeur d’Alene — $20 million.

l Lewiston — $16.2 million.

l West Ada (formerly Meridian) — $14 million.

l Nampa — $12.9 million.

l Lake Pend Oreille — $12.7 million.

Elsewhere in north central Idaho:

l Moscow — $11.75 million.

l Orofino — $2.68 million.

l Potlatch — $1.74 million.

l Troy — $995,000.

l Genesee — $884,932.

l Kendrick —$799,317.

l Whitepine — $869,611.

l Kamiah — $647,000.

l Highland — $499,000.

l Nezperce —445,000.

l Cottonwood — $325,000.

But there’s nothing supplemental about these levies. The money pays for teachers, textbooks, heat and lights — hardly extras. And if you dou bt it, just consider the occasional district where a supplemental levy fails. Last year, it was Mountain View’s misfortune to discover just how much basic state support falls short of providing — as the state constitution promises — a “general, uniform and thorough system of public, free common schools.”

When voters rejected the levy last spring, the district, which covers Grangeville, Kooskia and Elk City, was wrestling with how to make up for a 30 percent loss in its general education budget.

Not only is the property tax dreaded in Idaho, but supplemental levies fall unevenly across the state. Well-off Idaho communities — usually larger and more urbanized — have 30 times the property tax wealth behind each student as the state’s poorest districts — typically smaller and rural. To keep up, parents in those poor districts either agree to cough up a lot more money or reluctantly watch their kids fall behind.

A year ago, the Idaho Center for Fiscal Policy reported disparity in property tax wealth had contributed to a funding gap where the richest districts put $17,300 behind each pupil’s education vs. a low of $6,200.

How does that happen when Idaho lawmakers have been striving to add substantial increases to the state budget?

The fact is Idaho started out behind and remained there. Its per pupil expenditure comes in at 50th out of the 50 states and the District of Columbia. That hasn’t changed in years.

Not only is state spending inadequate, it’s not reliable.

Lawmakers cut the school budget during the Great Recession. Likewise, in the current pandemic, Gov. Brad Little shaved spending by about 5 percent, although much of the loss has been backfilled by federal coronavirus relief dollars.

So even before legislators set the school budget every March, you’ll find voters going to the polls to approve supplemental funding they can count on.

Even when Idaho makes headway, it often struggles to cover inflation and enrollment increases, let alone keep pace with other states where budgets remain more robust.

The state could do more since its treasury is flush with cash, but Idaho’s overwhelmingly Republican Legislature — which convenes Monday — is more inclined to cut taxes.

Rising supplemental levies are far from the only lagging indicator of inadequate state support. Look no further than the more than a third of Idaho school districts — mostly rural — that operate on a four-day week.

What’s ironic here is how Idaho voters find themselves at cross purposes.

For instance, voters who tossed out the anti-teacher Luna Laws in 2012 then turned around and reelected the same legislators who enacted those laws.

Likewise, the patrons who would attach more taxes to their homes rather than interrupt their child’s athletic or music programs will turn around and reelect a Legislature whose spending priorities put more pressure on their property taxes.

Go figure. — M.T.