The national office of the IAM feared Boeing would locate future assembly of that plane someplace where nonunion employees would do most of the work. So the national IAM struck a deal with Boeing that called for rank-and-file machinists to convert their traditional pension plans to 401(k)-style retirement accounts.
They also agreed to changes in the medical benefits for local union members. From the perspective of the IAM's national leaders, the concessions are the price to pay for guaranteeing job security for thousands of local machinists.
Local machinists choose job security, reluctantly
Local leaders of IAM District 751 were not happy that their national leaders set up a deal with Boeing. From their perspective, the national leaders lost leverage to hang on to the current pensions and medical benefits by negotiating a deal two years before the current contract expires.
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Union leaders prefer negotiating deals close to the end of current labor contracts so they have the threat of a strike, which can force the company to make concessions.
In addition, Local 751 leaders felt the national leadership of the IAM underestimated the advantage the union has with Boeing because of decades of experience building and servicing thousands of Boeing planes. That's why many local members said Boeing would be foolish to locate the new 777X plant in a city or state with little or no experienced workers to build the new plane.
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Finally, the local members are upset that leaders from the national level were negotiating a contract that would impact local workers. In other words, local workers think their local leaders should have called the shots, not the national office.
It's unlikely that local members of IAM District 751 will call for a recount of the vote that approved the new Boeing contract by a slim 51 percent to 49 percent margin. However, the hurt feelings and bad blood between local and national machinists is likely to linger for many years.
—By CNBC's Phil LeBeau. Follow him on Twitter @LeBeauCarNews.