Patrick Osio, editor of HispanicVista .com, offers a smearfest editorial entitled "Why assume day laborers illegal?" (It's available at his site under the title "Brown day workers, White street corner beggars and Racists". However, for some reason, the title tag is "The US, Canada and Mexico must form a North American Security Force". Hmmmm...)

The smearathon starts out with this:

There is an assumption that day-job seekers outside a Home Depot or any other home improvement stores are illegal immigrants. Well, no, that's not quite right to assume they are illegal immigrants [because] their skin is brown.

Nothing like getting right to the unfounded charges of racism. Those who assume that most day laborers are illegal aliens do so because that's what the evidence indicates. Calling that racism just illustrates Osio's lack of argument.

The editorial goes on to complain about lazy white beggars. Given that some of those might be U.S. vets, that's generally a losing strategy. Why aren't they working at day laborer sites instead of begging? Well, perhaps it's because they're mentally ill or disabled or they wouldn't be welcomed at the local Spanish-speaking day labor center.

You'll note that an editor appears to have added the "[because]" part; perhaps Osio was frothing too much to write a correct sentence.

Let's look at a study of Southern California laborers. Bear in mind this is from 1999, and the percentage of illegal aliens has probably only increased:

...UCLA researchers over the past two years interviewed 481 jornaleros at 87 sites, including eight hiring centers built and operated by cities and nonprofit organizations. Although the majority of workers were recently arrived illegal immigrants who had few options for earning money, one-fourth were longtime U.S. residents who had been plying their trade at the same site for more than six years...

The study clarifies the demographics of day laborers, but those findings will come as little surprise to anyone who has observed the sites. Typically, workers are young, male immigrants from Mexico and Central America. Educational attainment varies widely, but more than half have less than six years of schooling.

Nearly all--about 95%--entered the United States illegally. And although some have since gained legal residency, the overwhelming majority remain undocumented...

Now, let's turn to Virginia:

In 2003, Fairfax County conducted a survey of its four labor sites, including Herndon, which involved interviews of laborers on two occasions. The laborers were not asked whether they entered the country legally, but one of the questions was "about barriers they may have encountered while trying to find full-time work," according to the county report on the study results.

County-wide, 85 percent of the laborers in the survey cited "lack of documents" as a barrier to finding employment.

I believe there's also a nationwide GAO study showing that 90% of them are illegal aliens, but I can't find a link to it.

If people assume that the vast majority of day laborers are illegal aliens, it's because they are. I wasn't able to find any advertising at Osio's site, nor did I find a link between him and Home Depot. However, I'll note that HD has formed a partnership with four "Hispanic" groups.