It is a bipartisan compromise - neither party wants to be tagged as being soft on illegals or lose the Hispanic vote by being accused of immigrant bashing so it is not a Democratic or Republican bill.
Here is a link to an article describing the negotiations.
President Bush helped plant the seeds of this year’s negotiations on Jan. 8, at a White House event celebrating the fifth anniversary of the No Child Left Behind Act. Mr. Bush pulled aside Senator Kennedy, and they went into a room off the Oval Office to talk about immigration.
A month later, Senator Jon Kyl, a conservative Republican from Arizona who would become an important figure in striking the deal, began meeting with other Republicans and administration officials to explore ways to find a legislative response to an issue with potent political and humanitarian ramifications.
When those talks progressed far enough, the Republicans on March 28 invited in Democrats like Mr. Kennedy, a longtime advocate of immigration changes, and Senators Ken Salazar of Colorado and Robert Menendez of New Jersey. What followed was a series of meetings around the Capitol, typically on Tuesday, Wednesday and Thursday nights, as the lawmakers, staff members, White House officials and two or three cabinet secretaries immersed themselves in immigration rules as part of unusually direct high-level negotiations.
I disagree with the amnesty provisions, but something has to be done. The bankruptcy of the current system and current bill is summed up in this op-ed piece:
As the most attractive land for would-be immigrants, America has the equivalent of the first 100 picks in the NBA draft. Yet through lax border control and sheer inertia, it allows those slots to be filled by (with apologies to Bill Buckley) the first 100 names in the San Salvador phone book.
Enforcement at the border is all bureaucratic inputs and fancy gadgets: principally, a doubling of the Border Patrol to 28,000, lots of high-tech sensors and four unmanned aerial vehicles (UAVs). And 370 miles of fence -- half of what Congress had mandated last year.
The amnesty is triggered upon presidential certification that these bureaucratic benchmarks are met -- regardless of what is actually happening at the border. What vacuous nonsense