to use it.

No surprise there

associated with the union movement generally.

Good choice for the candidate who, despite what Bernie folks would have you believe, has the strongest level of support from individual unionized voters and union endorsements.

Also called "Stronger Together." From February 2016.

Perhaps Obama also stole the words? I mean, they're novel with Verizon. At least nobody's claimed he's vile and owns the Democratic Party. (Yet?)

Note that the AFL-CIO also used it. http://www.aflcio.org/About/Stronger-Together Before Obama. Dang.

Perhaps they stole it from the Verizon headline (mind you, it's a headline, not what the workers carried on their Verizon picket line) ... Even before the Verizon folk knew they were going to write it.

No, that can't be it. Here it is, an AFL-CIO slogan cited by the CWA in 2014. http://www.cwa4900.org/newsletter/we-rise-stronger-together/ So the CWA editors saw it from elsewhere, before the CWA first saw it?

The AARP had it a bit before I can find the AFL-CIO using it: http://www.aarp.org/relationships/friends-family/info-11-2011/vieira.html It seems to have been around. Who knows what STDs it's picked up along the way.

And there was apparently a song in 1980 that had that as the title.

Strikes me as a case of "what you see is all there is." You know one fact that helped make a rhetorical point stand, and that one little bit of info made all the other facts unimportant. Invisible. Unnecessary. And even harmful to the cause.

It's quite a popular slogan, and Verizon workers don't own it, they were just the most recent people to use it. It was the unofficial theme of Obama's 2012 campaign:

It doesn't appear in the body of the article, it doesn't appear on their signs and/or posters.

It is a coincidence, nothing more.