Transcript for 'Definitely and imminently' filing suit against Trump administration: Xavier Becerra

And let's bring in Xavier Becerra, California's attorney general who is considering a challenge to the president's national emergency in court. Mr. Attorney general, can you say definitely that California will be filing a lawsuit and when that will happen? Martha, definitely, and imminently. And imminently Monday, nothing will stop you? No reason. We are prepared. We knew something like this might happen, and with our sister state we are ready to go. You know, the president seems to be focusing on a wall in Texas, not California. Are you confident your state has concrete standing to challenge this? What harm is he doing to California with this declaration or will you join other states? How will that work? We are confident there are at least a billion ways that we can prove harm and once we are all clear, all different states are clear, what pots of money taxpayers sent to D.C. He's going to read which congress dedicated to different types of services whether it's emergency response services or whether it's fires or mudslides in California, maybe tornadoes and floods in other parts of the country or whether it's our military men and women and their families that might have money taken away from them or whether it's money taken away from drug and addiction efforts like California, a number of states and the Americas will be harmed and we're all going to be prepared. The national emergencies act gives the president very broad authority on what qualifies an emergency. So where do you believe he's really overstepped his bounds given this very vague law? Well, he himself said it. He did not need to announce or declare a cris he did not have to call this an emergency. He has also said he knows he's going to lose in court and he's hoping that he can count on a conservative court in the supreme court to give him a victory because he knows he's going to lose all the way up the ladder of the courts, the federal court system. It has become clear that this is not an emergency not only because no one believes it, but Donald Trump himself has said it's not, but there is enough evidence to show that this is not the 9/11 crisis that we faced back in 2001. It's not the Iran hostage crisis we faced in 1979. It's not even the type of national emergency where we are trying to take action against a foreign enemy or to avoid some type of harm befalling Americans abroad, and so it's clear that this is not a national emergency. Let me stop you there. You talk about 9/11. There have been 58 national emergencies declared since the law was passed in 1976 including three by president trump. Most recently for violence in Nicaragua. Why should the president have authority to declare a national emr that, and not for this which he clearly does see as a national emergency? There certainly may be some declarations that are dubious just like this one is. But typically, our presidents have focused on issues where the national interests are clearly at stake. The national interests aren't at stake here. We have the lowest level of entries into the country by those who don't have permission than we have had in some 20 years. The department of homeland security itself has said to the president that it is more difficult to cross into the U.S. At our land borders than it has been in a long time, and so it's clear that this isn't an emergency. It's clear that in the mind of Donald Trump, he needs to do something to try to fulfill a campaign promise. That doesn't constitute a national emergency. That would require us to essentially stand down on all sorts of federal laws and also violate the U.S. Constitution. Okay. Thanks very much Mr. Attorney general. We appreciate you joining us. Thank you.

This transcript has been automatically generated and may not be 100% accurate.