AUDIE CORNISH, HOST:
President Trump will do something tonight he has not done before. With a partial government shutdown in its third week over his demands for a border wall, the president is making a national address from the Oval Office. Democratic leaders have demanded equal time. They'll respond after the president speaks.
NPR national political correspondent Mara Liasson joins us now for a preview. Mara, what is the president trying to accomplish with this Oval Office speech?
MARA LIASSON, BYLINE: The president's goal is to convince voters beyond his base of supporters that shutting down the government in order to get funding for a wall is the right thing to do. That's the only way that he can put pressure on Democrats to accommodate him. He has to convince people outside of his hardcore base.
So to do that, the White House has been expanding the justification for the wall. Instead of just talking about rapists and drugs and criminals coming across the border, they're also making the argument that women and children are being hurt.
So if the president can convince enough people that it's a border security and humanitarian issue, he could win this fight. But if it's just a debate about whether it's worth shutting down the government to build a wall, he'll lose.
CORNISH: As of right now, where do the negotiations stand between the White House and Congress?
LIASSON: What's been happening is instead of moving towards the Democrats, the president has been asking for more and more money for the wall than he did a few weeks ago. In the latest ask from the White House, they're requesting $5.7 billion for 234 miles of new steel wall. That's in addition to other money for detention centers and judges and technology, things that are not that controversial.
But what's interesting about this is that supporters of the president point out that in the last continuing resolution that the president signed, where Democrats agreed to $1.6 billion in steel fencing while they explicitly ruled out a concrete wall, the president's supporters are saying that the materials should make a difference. Democrats agree - agreed to steel fencing in the past. They don't want concrete. But that so far is not moving Democrats.
And the other problem is because the president has made the wall such a potent symbol of his presidency - his kind of No. 1 issue - it makes it harder for Democrats to compromise because they have a base, too, and those base voters - Democratic base voters see the wall as a symbol of everything they hate about Donald Trump.
CORNISH: Now, the president has been suggesting that one way out of this is to declare a national emergency, maybe use military funds to build the wall. Any chance that will come up tonight?
LIASSON: It might come up, but I haven't talked to anyone who predicts that the president will actually call for a national emergency tonight. He does have the power to declare a national emergency, to do an end run around Congress.
But the people I've talked to, including former advisers of the president, say he could do that. But it's too soon to do it. He first has to convince the public that the Democrats are unreasonable and won't negotiate because he's the one who initiated this shutdown. A national emergency has to be a last resort. Otherwise, it would look like a political stunt.
Now, some members of Congress would be just as happy for the president to do that because it gets the problem off their plate at a moment when Republicans are worried about some of their members abandoning ship and starting to vote with Democrats to open the government. Other Republicans feel very strongly about congressional powers of the purse. They say Trump would be usurping Congress's power to appropriate funds and act unilaterally on immigration policy - something they didn't like when Obama did it.
But the reason it's so appealing to some members of Congress - it would end the shutdown. And this strategy of declaring a national emergency, which is being pushed by some of the president's advisers, is, it allows the president to act his own - act on his own, using his legal authority and showing his supporters that he did everything he could to build the wall even if he ultimately loses in court. And believe me. There would be a court battle on this.
CORNISH: That's NPR's Mara Liasson at the White House. Mara, thank you.
LIASSON: Thank you.