Chertoff Emerges as Linchpin

"He was exceptionally effective," Kaplan said.

Senate Majority Leader Harry M. Reid (D-Nev.), who called for Chertoff to resign in January 2006 after DHS dropped Las Vegas from a list of high-risk cities eligible for increased security grants, had praise for the White House's involvement in the negotiations.

Reid criticized several provisions in the guest-worker and legalization proposal but told reporters yesterday, "I do say this about the White House: They said they would get involved in this, and they have. And I appreciate that."

Several Republicans who have called for stronger enforcement but oppose the bill declined to comment. But Rep. Peter T. King (R-N.Y.), ranking Republican on the House Homeland Security Committee, said that while the Senate "amnesty proposal" will weaken national security, Chertoff "has approached it in a rational way," adding: "He's articulate when he describes it, and he makes a good case for a bad law."

Former immigration officials said Chertoff has for two years carefully navigated between critiques from the right and left that the U.S. government could not be trusted to enforce the laws, and that existing laws are failing.

Sen. Johnny Isakson (R-Ga.), for example, had reservations about the proposal. But a two-day trip with Chertoff in April helped cement his support for the bill, as long as it delays the new visa programs until progress is made on border control measures.

Carl W. Hampe, immigration subcommittee counsel under former senator Alan K. Simpson (R-Wyo.), who championed 1986 immigration legislation, said Chertoff also helped shape the political environment via DHS's "criminal law-focused enforcement of immigration law," which "certainly scared some employers." He attributed the trend to Chertoff's tenure as former assistant attorney general for the Justice Department's criminal division.

Bill Yates, chief of operations for U.S. Citizenship and Immigration Services in DHS until last year, agreed that Chertoff's grasp of the debate is crucial, but said that will require him to stay deeply involved if the programs are enacted.

"He's got to dedicate a considerable amount of time to these issues," Yates said, because Chertoff's subordinates who oversee immigration agencies have little experience themselves. "I think very highly of him. I think it's just an enormous task, and he doesn't have that kind of knowledge base beneath him."