In discussing the Maryland Fair Share health care law or the Chicago retail wage law, a lot of liberals tsk, tsk the idea that it only applies to a limited number of businesses.  The New York Times today bemoans the "fractured" nature of reforms represented by the Chicago bill,

Yet almost all social reforms have been enacted piece meal, including the original minimum wage law (more on the flip):

In fact, the original Depression-era 1938 Fair Labor Standards Act applied only to certain large manufacturing and other firms involved in a limited definition of interstate commerce.  It would take decades for it to be extended to retail, local transit, construction, health care, and a range of other services.

But since we are talking about "large retail", the 1961 amendments to the Fair Labor Standards Act begins:

An Act To amend the Fair Labor Standards Act of 1938, as amended, to proride coverage for employees of large enterprises engaged in retail trade or service..

Note the emphasis on "large" and "retail."  The 1961  act only extended the minimum wage to retail employees in large retail stores, much like the Chicago bill approved by that city council.   It was only a number of  years later that employees in smaller retail stores along with a range of other industries were covered by the federal minimum wage.  (See here for the evolution of coverage under the Act).

For many political reasons, most social reforms are not enacted all at once.  Quite reasonably, governments experiment, seeing if regulations applied to one industry segment, especially larger employers most able to absorb higher costs, are successful.   

It is a perverse corporate trick to demand complete across-the-board regulation all at once as the condition for even experimenting with a reform.   In fact, all industries aren't alike, so differential regulation often is needed.  In fact, industries regularly go to government asking for exemptions from various regulations or for various tax breaks based on that exact argument.   So while businesses regularly demands differential regulation to relax taxes or regulations, they claim "discrimination" when they are subjected to higher tax or regulatory responsibilities. 

What is shocking is that so many liberals buy into this trick.   The courts never have.  In fact, in the New Deal case, West Coast Hotel v. Parrish, that marked the Supreme Court backing off from striking down economic regulation, the court explicitly upheld selective regulation, saying :

The legislature “is free to recognize degrees of harm and it may confine its restrictions to those classes of cases where the need is deemed to be clearest.” If “the law presumably hits the evil where it is most felt, it is not to be overthrown because there are other instances to which it might  have been applied.”

More recently, the Ninth Circuit Court of Appeals upheld a Berkeley ordinance that created a higher wage just for businesses in a special tourist zone in its marina, citing West Coast Hotel and saying that judicial concern for equal protection is based on concern for “vulnerable” persons and that “a number of large businesses that occupy and profit from prime real estate can hardly be considered vulnerable.”  Quoting other Supreme Court precendents, the Court noted:

‘[R]eform maytake one step at a time, addressing itself to the phase of the problem which seems most acute to the legislative mind. The legislature may select one phase of one field and apply a remedy there, neglecting the others.’ ” Id. (quoting Williamson v. Lee Optical of Okla., Inc., 348 U.S. 483, 489 (1955))

Those who worry about "singling out" Wal-Mart or retail businesses or any subset of firms for initial reforms are fundamentally ignoring the whole history of progressive legislative change.  It has inevitably been an incremental, piece-meal endeavor.   The comprehensive laws people celebrate today are the product of decades of incremental amendments based on original piecemeal reforms.So celebrate the Chicago ordinance to raise wages for employees at large retailers.  Yes, it's a piecemeal reform but that is the rock on which cathedrals of broader change are built.  Liberals should remember their own history in understanding that basic fact.