This isn't amnesty for the millions of illegal aliens already here. Amnesty would be permanent resident status or citizenship, neither of which are being offered.
Note how carefully this is all crafted. There is nothing wrong with immigration. There is something wrong with illegal immigration. Those who have committed the illegality are offered a chance to plead guilty, pay their debt to society and become temporary workers in the US. Many will become citizens. Many will serve in the military.
What's going on here is a lot of folks got ready to oppose the policy based on DU planted stories. The reality is pure, Bush Americanism.