President Donald Trump will speak directly to the nation on Tuesday evening as a government shutdown enters its third week, and Democrats on Capitol Hill continue to refuse to fund border security and a border wall that Trump promised the American people.

Trump’s planned Oval Office address, which will be nationally televised on every major network and is expected to last approximately eight minutes, raises the stakes of this current political impasse to one of the biggest moments of Trump’s presidency.

The government shut down in late 2018, before Christmas, when Senate Democrats refused to back a House-passed government funding bill that would have provided more than $5 billion in funding for the wall. The House had passed the measure as one of its last acts at the end of eight years of GOP control of the lower chamber of Congress, but the Senate could not pass it because Senate Democrats lined up to prevent it from reaching the necessary 60-vote threshold.

The impasse led to a funding lapse, causing a partial government shutdown that has seen hundreds of thousands of federal workers furloughed and several departments and agencies of the federal government partially closed except for essential services.

The shutdown lingered through the Christmas and New Years holidays into 2019. Then, on Jan. 3, at the beginning of this year, the Democrats took over the House of Representatives with the majority they won in November’s midterm elections.

When Democrats took over, they passed funding measures without border wall money, but the White House – through the Office of Management and Budget (OMB) – has threatened to veto those. The Senate, meanwhile, which remains under GOP control, has per Senate Majority Leader Mitch McConnell refused to take up any legislation that the president will not support–and the president is standing by his demand for border wall funding.

Trump will take to the airwaves at 9:00 p.m. Eastern time on Tuesday evening, when he will make what White House officials say will be an approximately eight-minute-long address directly to the American people as the commander-in-chief, arguing that there is a national emergency and crisis that demands a solution including a wall or barrier along the U.S. border with Mexico.

Previously, support for a barrier along the border was not something that was controversial or partisan–Democrats backed, during the George W. Bush administration, the Secure Fence Act en masse. Democrats have also previously said they support securing the border, but many of them will not explain how they intend to do so without a barrier.

Trump’s crusade for a wall along the border began in the early days of his campaign for the White House, which he launched from Trump Tower in New York City in the summer of 2015. It became the central theme of his campaign for the presidency, and crowds at his rallies would chant “build the wall!” repeatedly in sold-out venues across the country.

In an Oval Office interview with Breitbart News at the beginning of his presidency, President Trump explained the importance of a wall along the U.S. border with Mexico in order to prevent drugs and crime from flowing freely across the barrier-less border, as they do now.

“We’re going to have a wall,” Trump told Breitbart News. “The wall is ahead of schedule. We’re going to have a wall and it will be a great wall and it will stop the drugs from pouring in and destroying our youth. And it will stop people from coming in that aren’t allowed to come in.”

Trump has maintained throughout his presidency his commitment to building the wall, and he has battled with Democrats hellbent on opposing it every step of the way. Three weeks into the shutdown, Trump now takes his most dramatic step in the push for the wall: an Oval Office address, televised directly to the American people.

The power of the backdrop of the Oval Office, when used effectively, has helped presidents in the modern era deliver major speeches, such as when Ronald Reagan soothed the nation after the Challenger crash or when John F. Kennedy delivered news of the Cuban Missile Crisis to the country.

The Oval Office is viewed as the power center of the world, as it is where U.S. presidents make decisions, and it is a physical representation of the office they hold. One of the key powers of a president is that of what is called the bully pulpit, something that allows a president through actions like this and other types of speeches and communications to draw attention to things the president wants the country and the world to focus on.

An Oval Office address is the most extreme and intensified version of the use of the bully pulpit power and aims at swaying public opinion in the president’s direction and rallying the nation together behind a unified cause.

Trump taking this drastic step also means he’s betting it all on the wall. To win, he has to come out the other end of a divided Washington with a border wall in tow–or having given an Oval Office address and then failing would mark a significant defeat for a president.

The president has said he is willing to drag this fight out for months or even years if necessary to get the border wall from the Democrats on Capitol Hill. The Democrats say they are not willing to give him the wall.

It is unclear where this battle goes from here, but the president is scheduled to tour the U.S. border with Mexico on Thursday–just two days after he delivers this historic address from the Oval Office.