Let me get this straight. The arbitrator has proposed that fire fighters be paid extra in exchange for undergoing drug and alcohol testing. And our city councilors are poised to go along with this plan.

I’m really puzzled about this. I thought drug and alcohol testing was not a burden—instead, it was about fire fighters’ own safety. If you were a fire fighter hanging from a handle on the side of a fire truck, wouldn’t you want to be assured that the guy or gal driving that truck was sober? Wouldn’t you want to know that the person beside you running into that burning building and watching your back had their wits about them? If you were a fire fighter’s husband or wife, wouldn’t you want this kind of protection for your spouse?

But apparently it has nothing to do with taking a sensible step that provides for the fire fighters’ own safety. It’s only about money.

Now I don’t really know or care whether Boston has the money to pay the fire fighters. I care more about the change in my heart:  As a self-respecting, liberal Democrat who detests Dick Cheney and large self-serving corporations, I would expect to be a union supporter. I was once in a union myself — well, it was the National Writer’s Union, so it may or may not count. But now, I realize, I am no longer a supporter of unions, at least the public sector ones.

How can this be? It’s because they have deserted the common weal.

I used to think unions were good. Coal miners, auto workers, hotel workers—unions made life fairer for them. The unions’ success made their members more prosperous, boosted their communities, and brought workers who had been exploited into the mainstream. Unions counteracted the selfishness and greed that corporations could easily fall prey to and that people with a moral compass couldn’t abide.

And most of us were willing to pay for fairness and a living wage for union workers. If the coal or auto industry charged more for their products so that workers would have better pay and safer working conditions, the higher price was worth it for the good of all of us.

But it hasn’t worked out that way with public sector employees. Instead, union actions now seem to conflict with the public good. Boston’s teachers’ union fought against energetic Teach for America college graduates leading classrooms. The union’s objections to charter schools, longer school days and longer school years has been counter-productive to students’ progress. Most of the public sector unions’ actions in the last few years haven’t been good for our kids or us.

Want to volunteer at your branch library to help cut costs? You can’t. Union rules allow for no volunteers performing tasks a union librarian does.

Public sector unions in some Massachusetts cities and towns won’t sign onto the state’s insurance plan, which would relieve taxpayers and maintain health care insurance to a standard that most of us put up with.

In the case of teachers, it’s even a question in my mind whether their lives and and pay are better than before unionization. If one reads the contract benefits touted on the Boston Teachers’ Union web site, they are uncannily like the benefits I got when I was a public school teacher 40 years ago—before unionization. I was satisfied with my pay as a second-year teacher since it was about the same as my husband’s pay as a first-year lawyer. So, did unionization improve benefits or raise pay? It doesn’t seem so since the discrepancy between the pay of a seasoned teacher and a first-year lawyer can now be as much as $100,000.

But whether the teachers’ lot has improved or not, unions face problems if they can’t count on people like me to support them. In fact, they and other unions can’t necessarily count on the support of the heavily Democratic Massachusetts legislature, which has in recent years walked away from the teachers’ unions especially. “It’s defending the indefensible,” says state Rep. Marty Walz.

Walz says that the public employee unions are not modernizing. She says the teachers’ unions, in particular, would be helped immeasurably if they promoted sound educational policies along with teachers’ rights and pay.

So far, the city council has not seemed to understand what many Massachusetts legislators have come to believe. Public sector unions that promote their own narrow and self-involved interests to the detriment of the public they are supposed to serve won’t have the support of a public. City councilors should remember that as they consider what to do about the fire fighters.