The public may not have much noticed the Janus v. AFSCME decision from the US Supreme Court, but the unions are reeling and with good reason. Both the NEA and the AFT stand at a precipice, not at all certain how to maintain the power they're long accustomed to wielding.

The fast flowing pipeline of dollars from teachers to unions ($600 million a year, nationally) is bound to be disrupted and here's why: about half of teachers have some pretty tall disagreements with unions. Several independent surveys administered by the now defunct Ed Sector as well as Public Agenda consistently report that only half of all teachers see their union as 'essential,' and half consider their dues too high, their political activity too tied to the traditional Democratic party and (here's where I think the real opportunity surfaces) their positions on education issues counter to schools' paramount interests.

It's not that teachers don't see the purpose of unions, so for those who would wish the Janus decision were the demise of unions, that's not in the cards. On unions' core functions, nearly all teachers give high marks: defending against claims by parents and students, going head to head with school districts, and bargaining for greater pay. But as any PBS station manager can tell you, just because viewers wouldn't have missed an episode of Downton Abbey doesn't mean they're inclined to donate during Pledge Week.

Here's what I am guessing the Post-Janus world will look like initially.

There will be the launch of a Madison Avenue-worthy campaign which makes the case for union membership and the sensible notion that teachers have a personal responsibility to pay their fair share.

There will definitely be more teacher strikes (they've already been announced), but no doubt there will be one too many. The unions won't be able to help themselves from squandering the good will engendered in last spring's strikes, reserved for those states where teachers were without question getting a bum deal.

There will be all sorts of laws passed that give unions better access to newly hired teachers.

There will then be all sorts of lawsuits and eventually another ruling from the Supreme Court that nullifies these new laws.

So what else can the unions do? There's one move that might keep more teachers in the fold, but it's not clear that current leadership at either union will consider it. They should rethink their combative stand on those issues which directly impact teachers and students, starting with their defense of really weak or toxic teachers.

With ample cash on hand, unions have long taken to an extreme their obligation to defend every teacher—which is why some districts estimate the cost of firing a single teacher at over $200,000. With the two unions being the largest contributor to American political campaigns, state laws they pushed to pass now make it impossible to fire a mathematics teacher who can't teach math. A drunk math teacher? Maybe, but by no means assuredly.

More than half of all teachers don't agree with the unions' to-the-death defense of some teachers. That's because there's nothing that drags teachers down more quickly than having to work alongside teachers who don't do their jobs well. When former teachers cite poor working conditions as the most common reason they leave the profession, they generally aren't referring to unclean bathrooms. They want to be surrounded by teachers who care as much as they do.

Most teachers also recognize the harm yielded by seniority rights, though those rights are cherished by unions. That's because teachers see first-hand the harm of such rights. As novice teachers, many were assigned to impossible jobs in the toughest schools, while veteran teachers moved on to take less challenging positions. Few teachers have fond memories of their first year of teaching, knowing how they unwittingly let their students down.

Well before Janus, teachers unions were struggling with declining membership. Janus is a symptom, not the source of unions' troubles. It would be a mistake to wish for the demise of teachers unions, as there needs to be a check on school districts' own considerable, often callously inflicted, power over teachers. However, unions cannot continue business as usual, giving higher priority to individual teachers over the health of teaching profession at large, or showing preference to one group of teachers (veterans) over another (novices). They should not hold positions that place students at risk, because that is why teachers are in this profession, for the sake of those students.

The path to a more certain future lies in those lessons. 

An earlier version of this editorial appeared in the Minnesota Star Tribune.