Migrant 'caravan' gathers on US-Mexico border for final push

A mother dresses her child at the Alfa & Omega migrant shelter in Mexicali, Mexico, Thursday, April 26, 2018, as they travel north with a caravan of Central American migrants. The caravans have been a fairly common tactic for years among advocacy groups to bring attention to Central American citizens seeking asylum in the U.S. to escape political persecution or criminal threats from gangs. (AP Photo/Hans-Maximo Musielik)
A migrant family gets ready for the three hour bus trip to Tijuana, at the Alfa & Omega migrant shelter in Mexicali, Mexico, Thursday, April 26, 2018, as they travel with a caravan of Central American migrants. The caravans have been a fairly common tactic for years among advocacy groups to bring attention to Central American citizens seeking asylum in the U.S. to escape political persecution or criminal threats from gangs. (AP Photo/Hans-Maximo Musielik)
A child walks in the patio of the Alfa & Omega migrant shelter in Mexicali, Mexico, Thursday, April 26, 2018, as he travels with a caravan of Central American migrants. The caravans have been a fairly common tactic for years among advocacy groups to bring attention to Central American citizens seeking asylum in the U.S. to escape political persecution or criminal threats from gangs. (AP Photo/Hans-Maximo Musielik)
Migrants rest in the patio of the Alfa & Omega migrant shelter in Mexicali, Mexico, Thursday, April 26, 2018, as they travel north with a caravan of Central American migrants. The caravans have been a fairly common tactic for years among advocacy groups to bring attention to Central American citizens seeking asylum in the U.S. to escape political persecution or criminal threats from gangs. (AP Photo/Hans-Maximo Musielik)
A mother who is part of a caravan of Central American migrants, holds a child after a cold shower at the Alfa & Omega migrant shelter in Mexicali, Mexico, Thursday, April 26, 2018. The caravans have been a fairly common tactic for years among advocacy groups to bring attention to Central American citizens seeking asylum in the U.S. to escape political persecution or criminal threats from gangs. (AP Photo/Hans-Maximo Musielik)
A Honduran migrant who is traveling with a caravan of Central American migrants walks with her two children to a shelter in Tijuana, Mexico, Wednesday, April 25, 2018. The caravan of mainly Central American migrants are planning to request asylum, either in the United States or Mexico. (AP Photo/Hans-Maximo Musielik)

Migrant 'caravan' gathers on US-Mexico border for final push

A mother dresses her child at the Alfa & Omega migrant shelter in Mexicali, Mexico, Thursday, April 26, 2018, as they travel north with a caravan of Central American migrants. The caravans have been a fairly common tactic for years among advocacy groups to bring attention to Central American citizens seeking asylum in the U.S. to escape political persecution or criminal threats from gangs. (AP Photo/Hans-Maximo Musielik)
A migrant family gets ready for the three hour bus trip to Tijuana, at the Alfa & Omega migrant shelter in Mexicali, Mexico, Thursday, April 26, 2018, as they travel with a caravan of Central American migrants. The caravans have been a fairly common tactic for years among advocacy groups to bring attention to Central American citizens seeking asylum in the U.S. to escape political persecution or criminal threats from gangs. (AP Photo/Hans-Maximo Musielik)
A child walks in the patio of the Alfa & Omega migrant shelter in Mexicali, Mexico, Thursday, April 26, 2018, as he travels with a caravan of Central American migrants. The caravans have been a fairly common tactic for years among advocacy groups to bring attention to Central American citizens seeking asylum in the U.S. to escape political persecution or criminal threats from gangs. (AP Photo/Hans-Maximo Musielik)
Migrants rest in the patio of the Alfa & Omega migrant shelter in Mexicali, Mexico, Thursday, April 26, 2018, as they travel north with a caravan of Central American migrants. The caravans have been a fairly common tactic for years among advocacy groups to bring attention to Central American citizens seeking asylum in the U.S. to escape political persecution or criminal threats from gangs. (AP Photo/Hans-Maximo Musielik)
A mother who is part of a caravan of Central American migrants, holds a child after a cold shower at the Alfa & Omega migrant shelter in Mexicali, Mexico, Thursday, April 26, 2018. The caravans have been a fairly common tactic for years among advocacy groups to bring attention to Central American citizens seeking asylum in the U.S. to escape political persecution or criminal threats from gangs. (AP Photo/Hans-Maximo Musielik)
A Honduran migrant who is traveling with a caravan of Central American migrants walks with her two children to a shelter in Tijuana, Mexico, Wednesday, April 25, 2018. The caravan of mainly Central American migrants are planning to request asylum, either in the United States or Mexico. (AP Photo/Hans-Maximo Musielik)