It remains to be seen what concessions the Service Employees International Union can pry from BART management in ongoing contract talks, but we already know the union needs a remedial class in public relations.

When local President Roxanne Sanchez last week told the BART board of directors, "We will be prepared for the bloodiest, longest strike since the 1970s," she might as well have added, "and we couldn't care less about the people who ride the trains or the cost containment needed to keep the agency operating."

The workers want raises, dammit, and not the 8 percent over four years that management offered. They want 5 percent per year.

If they must contribute toward pensions -- up until now, they've paid nothing -- they should be Junior Mint-sized contributions, say 1½ percent, not the big 5 percent Hershey bars that management seeks.

They want their medical coverage to stay affordable, like the $92 per month they currently are charged, not the whopping punch in the kisser that employees in the private sector pay.

BART can afford all these things, of course, because it is rolling in so much money that it only needs government subsidies to pay for about one-third of its expenses.

Those who sympathize with the workers -- I heard from a sympathizer last week -- come armed with two recurring arguments: 1) Salaries for BART workers are capped at unrealistically low levels; and 2) workers are denied the opportunity to participate in Social Security.

As far as they go, the points are correct. But let's dig beneath the surface.

It's true, for instance, that train operators top out at a salary of about $64,000. When I studied this newspaper's public salary database, the first six train operators I came across earned an average base pay of $63,648. Of course, those same six averaged more than $69,000 apiece in overtime. The first six electricians on the list averaged about $75,000 in base salary -- and more than $44,000 in overtime.

It's true that BART workers are ineligible for Social Security, toward which most of us pay 6 percent of our earnings. They are eligible, instead, for a more generous retirement fund toward which they have been paying nothing. For those six train operators, BART paid about $13,000 toward each of their pensions in 2012. For the six electricians, it was closer to $15,000.

What about union concerns over increased health insurance costs? BART workers should talk to BART customers to see if $92 a month is what everyone else pays.

Union negotiators' most recent drumbeat has been about the hefty compensation packages given top management. They're in sharp contrast to blue-collar workers, for sure, but the same disparity exists in every industry known to mankind. Would you be surprised that vice presidents and directors at Ford make more than assembly line workers?

Public support is an important negotiating tool. It pressures those held in disfavor to bend. But the workers' demands aren't resonating with the public, which is why they're upset. They're bargaining from a position of weakness.

The sympathizer who contacted me wanted to know why a columnist would portray ordinary working stiffs as unreasonable and out of touch.

It's because in this instance the working stiffs are unreasonable and out of touch.

Contact Tom Barnidge at tbarnidge@bayareanewsgroup.com.