"I'm going to continue to push here," said Rep. Jane Harman, D-Calif., who has emerged as a key player on the issue.
Senate Governmental Affairs Chairman Lieberman also has pledged to continue pushing the bill, sources said.
"Whether we can enact a law before November isn't clear, but we can start the process," Harman said.
The Democrats' resistance comes as White House Homeland Security Director Tom Ridge signaled today a willingness to accept legislation after he has a chance to settle into the new role, and said he would be "very open minded" to legislation at a later date. But added, "Right now, I don't believe I need statutory authority to do what the President has asked me to do."
On Wednesday, a bipartisan group of senators and House members began working to merge a handful of related homeland security measures into a single bill. Lieberman convened a closed-door session in the Capitol and said he would not back off the effort.
Later on Wednesday, President Bush hosted the top Democrats and Republicans on congressional Intelligence, Armed Services and Government Affairs committees to give a status report on the administration's efforts to fight terrorism. He also asked Congress to hold off on legislation in order to give the White House more time to set up its Office of Homeland Security.
After the meeting, one key member--Senate Intelligence Chairman Bob Graham, D-Fla.--agreed to back off. "When the President of the United States has a position on that ... it has influence," Graham said.