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Whatever deal Congress makes to keep the government open, it's clear President Trump isn't getting as much money as he wanted to build a border wall. The president's been talking about getting other funds to pay for that wall. NPR's David Welna looks at how he might do that.
DAVID WELNA, BYLINE: Congress is likely to give Trump less than a quarter of the $5.7 billion he sought for a wall. He seems unconcerned. Last night, Trump tweeted that such funding would, quote, "be hooked up with lots of money from other sources." Earlier in the day, he said this.
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PRESIDENT DONALD TRUMP: I'm thrilled because we're supplementing things and moving things around. And we're doing things that are fantastic and taking from far less - really, from far less important areas.
JIM DYER: I constantly scratch my head when I hear either the president or one of his representatives talking about how they're going to get the money.
TRUMP: That's Jim Dyer, a former longtime Republican staff director for the House Appropriations Committee. Any money the president spends, he says, has to be authorized by Congress.
DYER: The Constitution is pretty specific about how dollars are procured. And the Constitution gives that power to the appropriators, and it gives it to the Congress. If you're going to try to bypass the Congress in doing this thing, I think you're going to end up in the courts, and I'm not too sure you're going to want to do that either.
WELNA: One way Trump could get around Congress is by tapping more than $800 million in a Pentagon counterdrug fund to build a wall. Todd Harrison is a military budget specialist at the Center for Strategic and International Studies.
TODD HARRISON: He has pretty broad discretion in how that counterdrug money gets used, as long as it's for some sort of a, you know, counterdrug purpose. So he could do that without signoff from Congress, but it would be limited to the money that's available in that account, which is far below the $5 billion the president has said that he would need.
WELNA: Trump could also tap military construction funds to build a wall. Former appropriations staff director Dyer says that would not go down well with Congress.
DYER: I can tell you from my own experience, once you try to unravel those decisions, you automatically not only attack the process that put them there, but you attack the people behind the process who made the value judgment that this is where the money should go.
WELNA: Trump has not ruled out declaring a national emergency to get more money for a wall. Here's Mick Mulvaney, his acting chief of staff, speaking Sunday on NBC's "Meet The Press."
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MICK MULVANEY: There's pots of money where presidents - all presidents have access to without a national emergency, and there's ones that he will not have access to without that declaration.
WELNA: Congress has given presidents broad powers to take swift action once they declare a national emergency. Franklin Delano Roosevelt did just that in 1941, six months before Japan attacked Pearl Harbor.
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FRANKLIN D ROOSEVELT: I have tonight issued a proclamation that an unlimited national emergency exists.
WELNA: FDR successfully invoked that emergency as Nazi troops stormed across Europe and possibly toward the U.S. Harold Relyea is a leading expert on national emergency powers who was, for many years, with the Congressional Research Service.
HAROLD RELYEA: Most emergency declarations have responded to what common sense among people in Congress and informed people and the public would say, yes, there's some kind of an emergency there to be dealt with.
WELNA: But today, with the nation divided over the need to build a wall, Relyea says, for Trump, a national emergency may be a much tougher sell. David Welna, NPR News, Washington. Transcript provided by NPR, Copyright NPR.