With the midterm elections just days away, a showdown is brewing between President Donald Trump and a caravan of thousands of Central American migrants, putting the issue of illegal immigration right back on the front burner of the political stove.

The caravasion started with just over a thousand migrants, but it has grown to an estimated 7,000 in the last two weeks. And there are two more caravans behind it. While sympathizers describe these migrants as an oppressed group fleeing gang violence, the group looks more like an invading force as it approaches the southern U.S. border.

Immigrants pleading for mercy and accommodation by a host country don’t chant “One way or another, we will pass.” Immigrants don’t riot and tear down fences and barriers at the border, as the caravan did when stopped at the Guatemala/Mexico border. Immigrants fleeing oppression and violence wave the flag of the country they seek to be adopted into, not of the nation they are fleeing. Immigrants respect the laws of the country to which they seek entry.

Despite warnings from President Trump and Secretary of State Mike Pompeo, the caravan continues to work its way to the United States. That, of course, prompts the question: If America is such a heartless, racist country, why do these migrants not stop in Mexico and seek asylum there?

No, they’re just demanding transportation through Mexico.

This week Trump declared, “To those in the Caravan, turnaround [sic], we are not letting people into the United States illegally. Go back to your Country and if you want, apply for citizenship like millions of others are doing!”

For reasons of principle as well as practicality, President Trump must stop this invasion. To fail to do so will simply result in additional waves of migrants trying to force their way into the U.S.

Earlier this year, declaring a crisis, President Trump ordered National Guard troops to the border, having deployed 2,100 to this point. Last week, Defense Secretary James Mattis announced he was deploying 800 military troops to the U.S./Mexico border, and this week he announced “Operation Faithful Patriot,” increasing that number to 5,200 troops, in addition to the 2,100 National Guard troops.

The forces will consist of army engineers, “combat engineering battalions with expertise in building temporary vehicle barriers,” three medium-lift helicopter companies, military police units, medical and logistics units, and three C-130 Hercules and a Boeing C-17 transport plane" ready to deploy [Border Patrol] personnel wherever they need to be at any time.“

Under the Posse Comitatus Act, military troops are not allowed to engage in law enforcement activities, meaning they can’t directly engage migrants. However, with the Army and Marine Corps troops handling logistical support, Border Patrol agents are freed up to secure ports of entry and intercept those attempting to cross the border illegally.

President Trump minced no words in taking a hard line, warning, "If [the migrants] want to come into the country, you have to apply, like other people… This caravan is not — they’re wasting their time.” And unlike the Obama administration’s “catch and release” policy, Trump stated emphatically that “we’re catching; we’re not releasing.”

That leads to the question of what to do with these thousands of migrants when they reach the border.

President Trump said his administration will build tent cities for the asylum-seekers, and no one in the caravan will be allowed to enter without following the legal procedures. Current procedure for the U.S. Customs and Border Patrol (CBP) regarding asylum-seekers is to detain them in shelters on the Mexican side of the border until the CBP is prepared to process their requests.

In order to be granted asylum, migrants must prove a legitimate fear of persecution in their home country as a result of their race, religion, nationality, political ideology, or as a member of a persecuted social group.

Until recently that has been easy because, as U.S. Citizenship and Immigration Service spokesman Michael Bars explained, “The extremely low bar for establishing credible fear is ripe for fraud and abuse … a credible fear referral doesn’t equal asylum status, but it does earn a free ticket into the U.S., allowing individuals to disappear into the interior to live and work illegally.”

Hence President Trump’s determination to hold applicants in tent cities pending the resolution of their asylum application.

Attorney General Jeff Sessions has been narrowing the requirements for asylum, including disqualifying asylum applications presented solely on the basis of domestic abuse or gang violence. While percentages of approved applications have been high to this point, these policy changes will likely reduce that number.

While Trump’s critics warn that his hardline stance will result in an electoral backlash, they seem to forget that decades of refusal to deal with illegal immigration by former presidents and members of Congress is exactly how Donald Trump, a man with no prior political experience, defeated 16 highly qualified Republican primary challengers, and then a Democrat candidate with decades of political experience and a fearsome political machine behind her.

Trump alone made dealing with illegal immigration the unapologetic centerpiece of his campaign, and the American electorate rewarded him with the nation’s highest office.

So while the politicians and pundits continue to be baffled by Trump’s unshakeable support among his base, and a growing number of independents, the truth is quite simple: Agree or disagree with his policies, Donald Trump is a politician who actually keeps his promises.