'The wall is dead': MSNBC analyst explains how Democrats will win big off Trump's failure on 'number one promise'
President of the United States Donald Trump speaks at the general political discussion during the 72th session of the UN Assembly in New York. (Shutterstock)

In the 2016 presidential election, Donald Trump famously promised to build a wall along the nation's southern border and gets Mexico to pay for it.

The promise of having Mexico pay for the wall was quickly abandoned after Trump took office, despite Republicans having control of all three branches of government.

But in December Trump walked away from a bill to fund the federal government in a last-ditch effort to get some funding for his proposed border wall, causing a standoff that few observers, including members of his own party, believe will work out for him.

On Friday, MSNBC host Ari Melber discussed the guest Jonathan Alter, who explained why the shutdown is now a huge opportunity for Democrats.

"That's actually an opportunity for Democrats. And the reason why goes back to something that Karl Rove famously said: When you go after your opposition, go after their strengths, not their weaknesses," Alter said. It's a little counter-intuitive. Normally politicians like to change the subject from their opponent's strengths and focus on their weaknesses," he said. "So the wall was Trump's strength. It can also be his undoing if Democrats drive this message that on his number one promise he was not telling the truth and he failed."

Alter said there is no way the wall will be built now, as Trump has missed his opportunity.

"Something that not a lot of people have recognized yet: the wall is dead," he said. "It is not going to be built. There will not be a wall across the southern border of the United States. Not only because Mexico's not paying for it but because the Democrats control the House of Representatives and they won't appropriate the money. And even if they gave him $5 billion that's a rounding error—that's a tiny, tiny portion of that wall. So the basic dream that Trump had is dead. And once the American public realizes that and that he couldn't deliver on his biggest promise and that he was lying about it, that might hurt him."

Wath below.