President Bush recently appointed former Pennsylvania Gov. Tom Ridge as head of the new Office of Homeland Security.
Lieberman's bill, which is cosponsored by Sen. Arlen Specter, R-Pa., would create a position with more power than Ridge has — including control over personnel, budget and spending.
"I don't think (Ridge) has been given all the tools to get the job done," Lieberman said, adding while it would be up to the president, Ridge might head the new department.
Rep. William M. (Mac) Thornberry, R-Texas, sponsor of a similar bill in the House, said uniting the groups in one organization would makes sure that "Border Patrol radios are talking to the Customs official radios.
"It would realign our government so we are better able to prevent and respond to homeland threats," Thornberry said.
The bill worries Border Patrol union members.
T.J. Bonner, president of the National Border Patrol Council, has relocated to Washington from San Diego for the rest of this year to lobby legislators to make sure the bill — or others like it — does not doom the union. Federal law prohibits employees involved with national security from being in unions.
"We have very legitimate fears," said Bonner, whose union claims 5,500 members, many in San Diego and Imperial counties. "This is a very real threat to our existence."
Bonner said the new department would be too large to manage, is incomplete without key parties like the FBI and CIA and does not address the problems that led to the attacks.
"If this had been in place, would it have made any difference in the Sept. 11 attacks?" Bonner asked. "The answer is no."
Union officials said decertification would lead many agents to leave the Border Patrol.
"It would be catastrophic," he said. "The Border Patrol has a difficult enough time hanging on to people as it is. Take away their protection and you will see an exodus of unparalleled proportion."
Leslie Phillips, a spokeswoman for Lieberman, said the senator wants to minimize the impact on union members.
"We are working with the unions," she said. "He is very concerned that civil servants retain all the rights they have."