A caravan of asylum seekers has made it to the Southern border of the United States, but it could be the end of the line for the hundreds who made it this far.

“At this time, we have reached capacity at the San Ysidro port of entry for CBP (Customs and Border Protection) officers to be able to bring additional persons traveling without appropriate entry documentation into the port of entry for processing,” Commissioner Kevin McAleenan said in a statement to Fox News.

Translation: Door is closed. No vacancy.

The commissioner said that many of the asylum seekers “may need to wait in Mexico as CBP officers work to process those already within our facilities.”

They keep on knocking but they can’t come in.

The San Ysidro border crossing can only hold around 300 people and authorities warned the caravan before it reached its destination that there would not be a way to house the massive group.

Demonstrators from the United States gathered at the border to support the asylum caravan and some have begged President Donald Trump to allow the migrants in.

“The only thing I would tell Mr. Trump is to have a conscious and to look at all the people and the way they suffer. Because the people, they are coming from those countries, they are not doing it for pleasure,” Osman Salvador Ulla Castro, from Honduras, said to Fox News. “They face danger and extortions and they are looking for a better life.”

Some of the asylum seekers attempted to enter the United States earlier on Sunday via a broken fence, but they were stopped by Border Patrol agents, Fox News reported.

“In several of these incidents, children as young as 4 years old, and in one case a pregnant female, were detected entering the United States illegally through a dark, treacherous canyon that is notorious for human and drug smuggling,” Rodney Scott, the United States Customs and Border Protection San Diego Chief Patrol Agent, said. “As a father myself, I find it unconscionable that anyone would expose a child to these dangerous conditions.”

In terms of the politics, this caravan is a major gift to President Trump and Republicans who are demanding a border wall. The video clips and photos of these migrants are a lock to be used during the midterm election campaigns for Republicans to appeal to those who agree with them on the immigration issue.

The president and Republicans could not have asked for a better scenario to prove the need for a border wall. And it was helped by those who attempted to sneak in via the “dilapidated scrap metal border fence.”

President Trump mentioned the caravan at his rally in Washington, Michigan on Saturday.

“Are you watching that mess that’s going on right now with the caravan coming up?” he asked the audience who started to boo. “Are you watching this? And our laws are so weak. They’re so pathetic. Given to us by Democrats. They’re so pathetic.”

He used that as part of the reason he said he will shut the government when the budget is next due if he does not get funding for the border wall.

“[I]f we don’t get border security, we’ll have no choice,” he said. “We’ll close down the country, because we need border security.”