How much of the immigration argument is racially motivated?

[Steven D]

It's 50/50. You're right that a lot of people irrationally fear undocumented aliens and make all kinds of stereotypes around them.
Referring to your numbered points. Number 1 is fallacious. There are all kinds of ways of getting around the I-9 (that's the form you're really talking about). There's fake ID cards, stealing social security #'s, dishonest employers, etc., etc.

Point 3 is debatable. You're right when you're talking about fast food jobs. What about construction jobs? It's an industry that once was a medium-high wage industry that is now a low-pay industry. Illegal immigration is in large part the reason, along with union busting, stagnant minimum wages, etc.

Point 4--see point 3. You're right that most illegal immigrants aren't going to work as software engineers. But they might work as carpenters, electricians, all kinds of other skilled trade positions.

That being said, the answer is not to deport everyone. That would be a human rights crime of terrible proportions. But it's time for an open debate about how much immigration we need, and how to control it so that we can have a working labor market.

That's not the 2 second Yahoo Answers soundbite answer, but I hope it's informative.