I think the best selling point is to use Germany as an example. Build the myth of how Germany is such a powerhouse because its unions actually work: a good union is not an adversary of the owner as much as it keeps the owner from being an adversary of the person working in his company. Thanks to unions, German companies have a stronger feeling of “we’re all in this together” and strikes are much, much rarer there. They are good for workers because then only a representative has to do the negotiations and keep in touch with the owners, leaving the guys on the floor and the foremen and whatnot to get on making great stuff.
Now, I said myth on purpose, because reality is (of course) much more complicated. But for a sales pitch, you need a myth. Use the myth of Germany doing better than unions, and add to it the myth of American can-do attitude being the trick to making better unions.
