The migrant ‘caravan’ is scheduled to make their border-wall requests for asylum starting on Sunday, setting up a test between the pro-migration groups and President Donald Trump’s pro-Americans policies.

The activists’ U.S. immigration lawyers are training the roughly 350 caravan migrants how to get asylum in the United States, likely starting on Sunday, while Trump’s immigration deputies have announced plans to deny asylum to migrants who did not seek asylum in Mexico.

The U.S. migration group excluded reporters from the legal training sessions, said the Associated Press.

About 20 volunteer U.S. lawyers gave legal workshops Friday just across the border in Mexico to Central American asylum seekers who traveled in a “caravan” that has been harshly criticized by President Donald Trump. Journalists were not allowed inside the sessions for about 300 migrants that took place at a civic group’s office, at Tijuana’s largest migrant shelter and at an art gallery in a building that once housed a cross-border tunnel used to smuggle drugs into San Diego. The lawyers gave information about the U.S. asylum process while the children of the mostly female migrants played. The migrants were warned they could face long periods of separation from their children and lengthy detention if they are allowed to stay in the U.S. by increasingly charging asylum seekers with illegal entry.

The group’s routine advice to migrants is to claim a “credible fear” of persecution if they are sent home. If deemed credible by a border officer and then by an immigration judge, federal law requires they be allowed to file a formal request for asylum.

Since 2011, hundreds of thousands of migrants have used the “credible fear” claims to get hearings, so there is a judicial backlog of roughly two years. The backlog — and the lack of detention space — means that hundreds of thousands of migrants have been released into the United States, where there can get work permits and jobs. That flood of cheap labor cuts the wages and status of the American blue-collar service-workers who are used by university graduates as maids, gardeners, cooks, and clerks.

Roughly 100,000 migrants have used the same “credible fear” tactic to get into the United States since Trump’s inauguration — partly because Democrats have blocked Trump’s border reforms. The National Post reported:

The Juventud 2000 migrant shelter, on the edge of Tijuana’s red-light district, is filled with dome-shaped tents to accommodate more than 200 arrivals. Its director, Jose Maria Garcia Luca, said two previous caravans in May and November of last year had about 100 people each. Those who sought asylum reported no significant delays entering the U.S.

Many migrants already know what to say. The Canadian National Post reported:

Taxi driver Jovanne Torres from El Salvador said Wednesday after arriving in Tijuana Tuesday that Trump’s attacks on the caravan makes him doubt whether he’ll succeed in getting asylum for himself, his wife and his daughters ages 4 and 10 months — but he still plans to try. Torres, 37, said he fled his hometown near the country’s capital of San Salvador and joined the caravan days after a gang threatened to kill him and his wife when he refused to give a free ride to a gang member. He thinks he could be killed if he goes home and decided against seeking asylum in Mexico because he wants to join relatives in Houston.

The caravan of Central Americans has also prompted a growing group of Mexicans to the border to make their “credible fear” claims, according to Fox News.

But Trump’s opposition worries some of the migrants. “Trump’s words have made it difficult for us,” one migrant said.

Trump’s deputies are telling the migrants that their refusal to seek amnesty in Mexico could bar them from filing a request in the United States. Officials are also suggesting they will try to fast-track the caravan claims so that migrants can be sent home before they must be released into the United States. Migrants carrying kids have to be released in 20 days if their asylum claims have not been resolved.

Migrants know the laws and are acting to maximize their chances. One family cited in the Washington Post is splitting up so that each parent separately carries a child into their asylum hearing:

Jeannette Gonzalez, 28, was traveling with her daughters, ages 4 and 10 months, and the girls’ father, to whom she is not married. He will go first with the 4-year-old, while she remains in Tijuana with the baby until the father and the older girl are released from U.S. detention. Then the family will attempt to reunite. The girls’ father, a forklift operator, will be killed if he is deported to El Salvador, Gonzalez said, because he has refused to work for a gang as a driver.

#BREAKING: Hundreds in caravan of migrants that traveled across Mexico expected to claim asylum in U.S. this weekend. pic.twitter.com/JJo0sSx5wM — Ryan Saavedra (@RealSaavedra) April 27, 2018

For more about Trump’s strategy to block the “catch and release” migrants, read this and this.