President Bush is preparing to address the American people on the controversial issue of illegal immigration. Mr. Bush will make a nationally broadcast speech Monday, highlighting the need for new immigration laws. George W. Bush The president will talk about an issue that has divided America: how to stem the tide of illegal immigration, and what to do about the estimated 12 million undocumented aliens in the United States. Some in Washington say the illegal immigrants are criminals and border security is the only answer. Others say there is no way to deport so many people, many of whom have already put down roots in communities across the nation, and steps should be taken to give them some sort of legal status. President Bush has been urging a middle ground. In his speech Monday he is expected to urge members of Congress to adopt a comprehensive approach that secures America's borders, while presenting illegal immigrants already in the country with a way to remain as guest workers. White House officials say the president has been looking at some new ideas and one is to bring in National Guard units to help with border security. The National Guard is the only branch of the military organized on the state level. Guard members usually serve on a part time basis, and their traditional role has been to help their states cope with emergencies. But in recent years, Guard units have been called up for extended duty in the war on terrorism. A few Guard members are already working to support the Border Patrol in some parts of the country, and White House National Security Advisor Steven Hadley says that support role could be expanded. Steven Hadley He spoke on CNN's Late Edition program. "The notion of using the National Guard to support the Border Patrol is not a new one. This is something that is already being done. It is not a militarization of the border," he said. "It is about assisting the civilian Border Patrol." Hadley said several lawmakers are enthusiastic about the idea of deploying thousands of National Guard troops along the border with Mexico. Among them is the top Republican in the Senate, Majority Leader Bill Frist. He also appeared on CNN. "I think that is the least we can do," said Frist. "Securing our borders is a federal responsibility. We need to act. We have failed miserably in the past." But Senator Patrick Leahy, the senior Democrat on the Senate Judiciary Committee, says he is concerned the Guard is already overextended with its commitments in Iraq. He told CNN more border agents should be in place, and the Guard should not be used. "We are stretching them pretty thin now and we are going to make Border Patrol out of them? What I wish they had done was when we asked them two years why don't you fund the Border Patrol positions that the Congress has provided? You know what we got from Homeland Security for an answer? Nothing at all," concluded Leahy. But Senator Leahy praised President Bush for advocating a comprehensive approach to the problem. Senate leaders say they hope to have an immigration reform bill acceptable to the White House completed in the next few weeks. They acknowledge the most difficult part of the legislative process will still lie ahead: reconciling their version of the legislation with the tough border security bill that cleared the House of Representatives late last year.