A s an American-born son of immigrants, I understand the historic power and promise of our immigration system. I also understand that it is a system that is currently broken and must be changed.

To that end, I spent many hours over the last two months with a core group of colleagues and members of the president’s Cabinet as we discussed, debated and negotiated provision after provision for an immigration reform bill. The talks were at times constructive, at times productive, but also at many times frustrating.

Last week some of my colleagues, along with the administration, began to settle on a blueprint for an agreement. Despite my objections, the framework had shifted far to the right of the bipartisan bill that passed the Senate with 62 votes last year. I took stock of the situation, the terms of the deal and where they fit in relation to my core principles and made a decision: I could not be on board with the deal being developed.

The basis for the agreement was a proposal the White House unveiled during a closed-door meeting in March. A year ago the administration had joined 23 Republican senators to support compromise reform legislation. This year it put down an anchor far to the right. The talks would naturally be pulled toward the administration’s proposal — it’s Negotiating 101.

Without question, my colleagues involved in the discussions all brought with them good-faith efforts, commitment and a willingness to listen, even if they were rooted in particular ideologies. But honest, hard work alone does not make for sound or responsible policy. I certainly do not believe it produced a fair or practical comprehensive immigration reform bill in this case.

Our country needs immigration reform that is strong on security and good for the economy, that preserves family values and that is fair, workable and comprehensive in nature. Instead, the result of negotiations was a deal that fails on several of these principles, which are vital for a practical system and for the values of our country.

The foremost of these is the bedrock principle of family — more specifically, the ability of American citizens or permanent residents to petition for their families to be reunified here. The deal struck changes the fundamental values of our immigration policy by making an advanced degree or skill in a highly technical profession the most important criterion for a visa. This nation has been built by immigrants who came here to achieve success, but the deal tilts toward immigrants whose success stories are already written.

Family reunification will be de-emphasized under this deal, serving to tear families apart. From a moral perspective, this undermines the family values lawmakers so often talk about. Practically speaking, a breakdown of family structure often leads to a breakdown of social stability. I took it to heart when President Bush said that “family values don’t end at the Rio Grande,” but this agreement, like his proposal before it, belies those words.

Under the deal, the unskilled workers who form a cornerstone of our economy by taking jobs most Americans would not are relegated to a truly temporary, Bracero-style worker program with no chance for permanent residency. Reality is that, without a light at the end of the tunnel, many who enter this program will go underground to stay in America, creating yet another class of undocumented workers.

Then there is the proposed pathway to permanent residency for the 12 million undocumented workers in this deal. One has to ask if it is truly a pathway or an unrealistic obstacle course.

The path includes years of waiting, up to $19,000 in fines and fees per family of four and “touchback” provisions requiring heads of households to return to their home countries before applying for re-entry. Certainly fines and penalties are necessary, but if they are made prohibitive, millions of undocumented workers may choose to maintain their current status. We would prefer to know who is here to pursue the American Dream and who is here to destroy it.

I said throughout the negotiations that with a massive, complex bill like this one, the devil is in the details. There are a number of details in this deal that would create an unfair and impractical immigration system, undercutting the more sensible provisions.

It is a deal that would have prevented my own parents — a carpenter and a seamstress — from coming to this country. I would like to think that they, like hundreds of millions of other immigrants who have helped build our nation, contributed to the strength and vitality of America.

The story of this legislation is not finished. We still have the historic opportunity over the next few weeks to craft tough, smart and fair immigration reform. It is my intention, through a series of amendments that get to the heart of the issues I have mentioned, to help lead a charge to improve this deal on the Senate floor. I know many of my colleagues are committed to the same issues of practicality, fairness and family values, and I will work with them to turn this unworkable deal into sound policy that we can all support.