Is it unrestrained greed keeping Bush from enforcing the laws on the books? What's a lame duck president to gain from it?
"What's a lame duck president to gain from it?"
You're asking that, seriously?
It's not complex. GWB has rich and powerful friends. The rich and powerful tend to be business owners. Now, if you employed 10,000 people making widgets, would you rather pay them $8/hour, or $4/hour?
Illegals work cheaper, and many are off the books, so no other benefits are required.
GWB helps the rich and powerful, and in return GWB will be rewarded. That's politics.
The lame duck president is also a leader of a party that does not want to alienate an important segment of their electorate, Hispanic voters and employers who gain from cheap labor.