15일 국가비상사태를 선포하는 도널드 트럼프 미국 대통령
15일 국가비상사태를 선포하는 도널드 트럼프 미국 대통령

WASHINGTON - The White House is defending President Donald Trump's declaration of a national emergency at the U.S.-Mexico border as multiple states prepare to file legal challenges and Democrats in Congress plan to vote their disapproval.

"He could choose to ignore this crisis, but he chose not to," Trump adviser Stephen Miller, an immigration hardliner, told Fox News Sunday.

Miller assailed former Republican President George W. Bush for what he called an "astonishing betrayal" of the U.S. nearly two decades ago when four times as many immigrants were illegally entering the United States as now. But Miller said the "bottom line" is that "you cannot conceive of a strong nation without a secure border."

He said Trump's action is "defending our own borders." He illegal immigration "is a threat in our country."

Miller said Trump's actions were justified under a 1976 law giving presidents authority to declare national emergencies, although none of the 59 declared since then has involved instances when a president has attempted to override congressional refusal to approve funding for a specific proposal.

Trump declared the national emergency on Friday to circumvent Congress, which had refused his request for $5.7 billion in wall funding, even as it approved $1.375 billion for barriers along about 90 kilometers of the 3,200-kilometer border. Trump plans to tap more than $8 billion in government funds authorized for other projects the build the wall, although lawsuits challenging the action are already being filed to block his transfer of money.

FILE - Border Patrol agent Vincent Pirro looks on
Border Patrol agent Vincent Pirro looks on near a border wall that separates the cities of Tijuana, Mexico, and San Diego, Feb. 5, 2019, in San Diego.

California Attorney General Xavier Becerra told ABC's This Week that his state and others would "definitely and imminently" file a legal challenge, arguing that people all over the United States would be harmed by Trump's move because the diverted money would not be spent on needed services.

"Typically our presidents have focused on issues where the national interests are clearly at stake," Becerra said about previous national emergency declarations. "The national interests are not at stake here. We have the lowest level of entries into the country by those who don’t have permission than we’ve had in some 20 years."

Acting U.S. Defense Secretary Patrick Shanahan said he thinks he has "a lot of discretion" in deciding which funds previously allocated for defense needs can instead be used to build a border wall. "You can trust the numbers in terms of the potential. Then you gotta marry it up with where the money would be spent."  But he said money designated for military housing would not be spent on the wall.

Trump said he declared the national emergency because he was unhappy with the amount of money Congress authorized.

"I want to do it faster," he said. "I could do the wall over a longer period of time. I didn't need to do this. But I'd rather do it much faster."

Trump's staunchest critics, including Democrats who have announced they are running against him next year and other lawmakers, have attacked his national emergency declaration as an end-run around the constitutional provision that U.S. funding authorization lies with Congress and noted that he said that he did not need to take action.

Democratic Congressman Adam Schiff, chairman of the House Intelligence Committee, told CNN, "If we give away, if we surrender the power of the purse… there will be little check and no balance left. It'll not be a separation of powers anymore, just a separation of parties."

Journalist Bob Woodward, who chronicled the first year of the Trump presidency in a best-selling book called "Fear," told Fox News he believes Trump made the national emergency declaration because "he looks strong. He looks tough to lots of people."

Trump centered much of his successful 2016 campaign for the White House on a vow to build the wall and make Mexico pay for it. He long since abandoned direct payment from Mexico, when its leaders rejected the idea, and instead sought congressional approval of the U.S. taxpayer funding.