Transcript for Trump to declare national emergency for border wall

breaking news from Washington. Looking at the white house where president trump will sign the border deal to keep the government open but also declare a national emergency in an attempt to bypass congress so he can get funds for his border wall. Sparking fierce backlash from some in the president's own party. Our chief white house correspondent Jonathan Karl has the very latest. Jon, this is setting a stage for a very nasty showdown between the white house and congress. Reporter: A showdown with congress and, Cecilia, a showdown with the courts. This morning the president plans to announce an end around around congress and spending more than congress has approved. This morning president trump plans to declare a national emergency as a way to get billions more in funding for his border wall. And it's a big wall. It's a strong wall. You're going to have to be in extremely good shape to get over this one. They would be able to climb mt. Everest a lot easier, I think. Reporter: A highly controversial move sure to be challenged in court but one the president has been telegraphing for week. We'll either have a win or I will declare a national emergency. Reporter: A win, he didn't get. Congress approving only a fraction of what he wanted for the wall. They did a spectacular job. Reporter: Overnight house speaker Nancy Pelosi and house Democrats celebrated the passage of the 1100-page funding bill, averting another shutdown. Neither Democrats nor Republicans got everything you wanted. Reporter: ABC news has learned the president will declare his plans to spend a total of $8 billion on the wall, even more than he had asked for in part by declaring the national emergency and shifting billions of dollars from the Pentagon's budget. Democrats say that would be an abuse of power and set a dangerous new precedent. It's not an emergency. What's happening at the border, a humanitarian challenge to us and the president has tried to sell a bill of goods. The president is doing an end around around congress. Reporter: ABC news learned the justice department warned the white house that the president's national emergency declaration would almost certainly be blocked, at least on a temporary basis by the courts. White house officials, however, tell me they are confident they would ultimately win this on appeal.

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