WASHINGTON – President Donald Trump will lay out his case for the border wall in a prime time address Tuesday from the Oval Office, but he has been making similar arguments in less high-profile settings for weeks amid the partial government shutdown.

Recurring themes have emerged that are certain to come up again during his address, which will be carried live on the nation's broadcast and cable news networks. Here's a look at some of the claims Trump frequently makes, and the context behind them.

Increase in drugs and crime

Trump has tried to frame the "crisis" on the border in easy to understand terms. Much of that messaging has focused on the idea that lax security has led to drugs and crime "pouring" over the border. Trump bases the claim on the idea that members of the MS-13 gang have committed violent crimes in some parts of the United States.

But there is missing context in Trump's characterizations. To begin with, the vast majority of illicit drugs captured at the border come through legal ports of entry, according to Trump's own U.S. Customs and Border Protection. For the first 11 months of the 2018 fiscal year, 90 percent of the heroin intercepted at the border and 88 percent of the cocaine, was captured at a legal port of entry rather than between those ports.

There is a similar caveat to Trump's claim on crime. The president and Republicans frequently point to roughly 17,000 people trying to enter the country who had been convicted of crimes in the United States or abroad in the first 11 months of 2018. But more than 60 percent of those people came through legal points of entry, including airports, according to Customs and Border Protection data.

National emergency

Both Trump and White House aides have cast the situation on the southwest border in recent days as a "security and humanitarian crisis." The idea that Trump may declare a national emergency to free up funding for the border wall emerged around the same time. Trump told reporters "absolutely, we can call a national emergency."

Democrats have cried foul and have threatened to sue but current law gives presidents broad authority to declare a national emergency. Trump's powers during an emergency are limited by law, but the White House and experts have pointed to provisions law that would allow him to redirect military and other construction funding for the wall.

Congress may pass a resolution to overturn the president's emergency, but it would require Trump's signature to take effect – meaning such a resolution is unlikely to be successful. Trump's order would almost certainly draw legal challenges and could be tied up in court, raising questions about the ability to begin construction in his first term.

Humanitarian crisis

The Trump administration has repeatedly cast the situation on the border as a “humanitarian crisis,” which they back up with statistics on the number of migrants referred to medical providers (50 a day, according to the White House) and what aides describe as “large populations” that are “abused on the journey.”

Democrats and other Trump critics counter conditions on the ground have been exacerbated by the administration’s policies, some of which are designed to discourage migrants from making the journey to the U.S. For instance, the administration’s decision to deny entry to migrants seeking asylum in the United States has meant returning those people to Mexico until their applications are processed.

That has created a backlog in which thousands of migrants are waiting on the Mexican side of the border.

Trump aides have countered that the old system allowed those people to enter the country before asylum was granted and then disappear from the view of immigration agents.

Meanwhile, federal detention centers on the border have been hitting capacity in recent weeks, forcing the administration to release hundreds of people into El Paso and elsewhere. The chaos has also been complicated by the partial government shutdown.

How many people cross illegally

The administration has also failed to put the number of people crossing the border into context. During a round of interviews to promote Trump’s border wall, Vice President Mike Pence told NBC News on Tuesday that the sheer volume of people trying to cross the southern border illegally constitutes part of the “crisis.”

"We're now seeing 60,000 people a month attempt to come into our country illegally on the southern border," Pence said.

The vice president overstated the actual number: 51,856 people were caught trying to illegally enter the country in November, and 51,001 were caught in October, according to U.S. Border Patrol data. But even those numbers remain at historic lows for the U.S.

During the 2000s, it was common for Border Patrol agents to arrest over 100,000 people each month. In two consecutive months in 2000, Border Patrol agents arrested more than 200,000 people.