The move­ment has stirred up inter­est among work­ers far beyond fast foods, includ­ing stu­dent work­ers, adjunct teach­ers and retail work­ers. The num­ber of peo­ple tak­ing part in the nation­al protests/​strikes have grown as well.

When McDonald’s stock­hold­ers meet on the leafy cor­po­rate cam­pus in sub­ur­ban Chica­go today and tomor­row, thou­sands of pro­tes­tors will be ready to greet them, accord­ing to orga­niz­ers of the fast-grow­ing Fight for $15 move­ment. Last year, in the first such con­fronta­tion, a few hun­dred peo­ple marched on and then blocked roads lead­ing on to the com­pa­ny prop­er­ty before police arrest­ed them.

But at the same time, the move­ment has focused very intent­ly on one com­pa­ny, McDonald’s, since it is the biggest fast-food fran­chise com­pa­ny in the world and helps set glob­al pat­terns. If the move­ment, pri­mar­i­ly fund­ed and ini­ti­at­ed by the Ser­vice Employ­ees Inter­na­tion­al Union (SEIU), can win vic­to­ries with the indus­try leader, it may be some­what eas­i­er to win the same changes at oth­er companies.

Also, the close atten­tion has allowed Fight for $15 to research McDonald’s more thor­ough­ly to find new vul­ner­a­ble points for attack, new meth­ods of bring­ing pres­sure and new allies. For exam­ple, SEIU, which has for sev­er­al years worked hard to build up glob­al labor a con­nec­tions, has report­ed­ly been able to rely on these unions in Europe to help pro­vide infor­ma­tion that led to charges against McDonald’s that it had ille­gal­ly avoid­ed tax­es. (Euro­pean unions have legal stand­ing to take action against and gain infor­ma­tion from McDon­ald’s that non-union Amer­i­can work­ers lack.) And in Brazil, unions have sued the multi­na­tion­al for dri­ving down stan­dards for workers.

In the Unit­ed States, the biggest protests so far came on April 15, when strik­ers and sup­port­ers told tax­pay­ers how they had to rely on tax-fund­ed pro­grams to sur­vive because McDonald’s did not pay enough — poten­tial­ly tap­ping into a big base of allies to force the com­pa­ny to pay liv­ing wages. But the protests also focused on abuse of work­ers, includ­ing expo­sure to health and safe­ty risks, racial dis­crim­i­na­tion and vio­la­tions of wage and hour laws. The movement’s atten­tion to those issues helped to make the case that work­ers need­ed not only the increased pay but also a voice — through a union — to demand safe­ty and respect on the job.

The movement’s charges have also raised legal ques­tions about whether McDonald’s cor­po­ra­tion is actu­al­ly a joint employ­er with fran­chisees, since it dic­tates so many con­di­tions at work. Such a deci­sion, for exam­ple, in wide­spread com­plaints now before region­al branch­es of the Nation­al Labor Rela­tions Board, would make the cor­po­ra­tion liable for dam­ages along with fran­chisees and require them to deal with work­ers over res­o­lu­tion of problems.

Indus­try observers have crit­i­cized McDonald’s man­age­ment and weak mar­ket per­for­mance in recent years, and the com­pa­ny has appoint­ed a new CEO. But the cor­po­rate board and man­agers have respond­ed to its prob­lems not by improv­ing prod­ucts or ser­vice but by spend­ing over $30 bil­lion dur­ing the past decade buy­ing back its stock. By arti­fi­cial­ly inflat­ing the stock’s val­ue, top man­agers pro­vid­ed short-term ben­e­fits to share­hold­ers, includ­ing exec­u­tives and direc­tors, but have short-changed both work­ers and fran­chisees — and have most like­ly harmed the com­pa­ny in the long term.

In one unusu­al alliance, SEIU has offered sup­port to many fran­chise oper­a­tors who claim they have been mis­treat­ed by McDonald’s. The union filed a com­plaint with the Fed­er­al Trade Com­mis­sion, which is respon­si­ble for over­see­ing the fran­chise busi­ness­es, about an imbal­ance of pow­er at McDonald’s that harms both work­ers and their imme­di­ate boss­es, the employ­ees. While the fran­chise oper­a­tors do not agree with every­thing that Fight for $15 advo­cates, the union’s will­ing­ness to help with legit­i­mate fran­chisee griev­ances helps to sep­a­rate some fran­chisees from their poten­tial nat­ur­al alliance with the cor­po­ra­tion and instead open up the pos­si­bil­i­ty of an even broad­er alliance with the work­ers in the industry.

Like­wise the cam­paign as a whole has great­ly raised expec­ta­tions about what the min­i­mum wage should be, prompt­ing even the fair­ly con­ser­v­a­tive Demo­c­ra­t­ic gov­er­nor of New York, Andrew Cuo­mo, to appoint a wage board that is quite like­ly to set a min­i­mum wage for the state’s food indus­try around $15 an hour with­in the next three months. Pro­gres­sive New York City Demo­c­ra­t­ic May­or Bill de Bla­sio is wait­ing in the wings to set the mark as high or high­er.

And the Los Ange­les City Coun­cil joined the ranks of U.S. cities tack­ling pover­ty wages and spi­ral­ing income inequal­i­ty through adop­tion of strong local min­i­mum wages. By a vote of 14 to 1, the coun­cil direct­ed L.A.’s city attor­ney to pre­pare leg­is­la­tion set­ting a $15 wage floor. The new rate will be phased in over sev­er­al years, reach­ing $15 in 2020 for large busi­ness­es and in 2021 for small­er busi­ness­es and cer­tain non-prof­its, and pro­vid­ing for future adjust­ments to be pegged to increas­es in the cost of living.

Unfor­tu­nate­ly, there is no clear road to union­iza­tion of these work­ers despite the scale, mil­i­tan­cy and clev­er­ness of their action, and in both the short and long run, hav­ing a union is essen­tial for the suc­cess of the work­ers and their cam­paign. At a time when the Supreme Court may under­mine exist­ing unions by deny­ing them the right to col­lect ​“fair share” pay­ments from non-mem­bers, the suc­cess of actu­al orga­niz­ing of a union by the Fight for $15 move­ment may prove cru­cial for estab­lish­ing a more favor­able pub­lic envi­ron­ment for work­ers to form — and keep — unions.