UAW President Bob King knows it will be difficult to organize the transplants.

As important as it was to win new contracts from Detroit’s Big Three over the summer, United Auto Workers Union President Bob King has made it clear that the “most important” goal during his tenure will be to begin the long-stalled process of organizing the foreign-owned “transplant” assembly lines that now dot the American landscape.

In the more than quarter century since the first, a Honda plant in Marysville, Ohio, opened, only three have voluntarily accepted the UAW – all because they were U.S.- Japanese joint ventures, one of which has now closed. Efforts to organize the other foreign-owned factories have failed, so far.

Now, it seems, the UAW is ready to try again, and while King told the Associated Press there’s no deadline nor official target, the wire report says it is “crystal clear” to union leaders that they need begin by targeting Japan’s second-largest automaker, Nissan.

It wouldn’t be the first time.  But an earlier drive at the maker, which operates assembly plants in Mississippi and Tennessee – the latter near its U.S. headquarters – fell flat when workers voted the union down. This time, the UAW appears to be hoping to tap worker frustration at the Canton, Mississippi plant where it claims the company is committing what the union described as both civil and human rights violations.

Burned before, the UAW has been cautious about getting too eager in its organizing efforts.  In fact, it has quietly attempted to talk with corporate executives, hoping to encourage them to permit an organizing drive and vote.  The carrot is that if the union loses it will walk away.  The stick is that if the company’s don’t cooperate the UAW will launch a global PR campaign and boycott.

“We have had some productive discussions with top leaders at Nissan,” King said in an interview with the AP. “We’re continuing that. We’re hoping that issues can be resolved with them.”

The wire service report drew a quick response from Nissan, spokesman David Reuter e-mailing TheDetroitBureau.com to say that, “Mr. King’s attempts to disparage Nissan are without merit. Our results and our reputation in the communities where we operate speak for themselves, and they contrast sharply with the image that the UAW is now trying to paint of Nissan.”

That said, Nissan may not be looking to declare war on the union, Reuter adding that, “The UAW’s attempts at organizing our facilities are not new to Nissan and we will respect the rights of our employees to decide whether to organize. However, each time the UAW has conducted a campaign that led to a union election at our Smyrna assembly plant, employees voted overwhelmingly against organizing.”

Losing another vote would likely be disastrous for the union’s image, according to industry observers, and could scuttle further organizing efforts – which insiders say explains why King’s team has been taking such a cautious approach to a drive it announced with much fanfare a year ago.

But such apprehension doesn’t mean the UAW is giving up.  The union has no choice.  From a nearly 1.6 million member peak in 1979 its ranks have fallen to barely 379,000, even after a modest 6% increase last year – its first since 2004.

While the UAW has been able to win promises from Detroit’s Big Three – who agreed to add thousands of new jobs as part of the contracts they signed this year – that will go nowhere near making up for the cuts the domestics have made just in the last decade.

As manufacturers from Japan, Germany and South Korea have set up shop in the U.S. they have added about 80,000 workers of their own.  Yet only three facilities were organized by the union, including a General Motors-Toyota venture in California that closed following the U.S. maker’s emergence from bankruptcy.  (Known as NUMMI, the facility will re-open next year to produce the new Tesla Model S battery sedan, but as of now it is expected to operate as a non-union facility.)

Meanwhile, the Ford-Mazda plant in Flat Rock, Michigan continues to be represented by the UAW – but Mazda plans to pull out of the operation when it transfers production of the next-generation Mazda6 sedan back to Japan.  That would leave only the Mitsubishi assembly plant in Normal, Illinois operating under UAW representation. That factory was originally opened as a joint venture with Chrysler.

The Mitsubishi plant has seen a fair amount of union-management confrontation over the years, an issue not ignored by the companies operating other transplants in the U.S.  They also recall the often bitter disputes between the UAW and Volkswagen, which operated the country’s first transplant, in Westmoreland, Pennsylvania.

The maker closed that factory about the same time the first Japanese plants began opening in the U.S.  Committed to rebuilding its once-dominant position among foreign brands, VW opened a new transplant facility this year in Chattanooga, Tennessee, but it notably declined to invite in the UAW.

Whether the union will be able to get workers to extend an invitation remains to be seen – and could depend on how well things go with a Nissan drive.