Trump saw eight prototypes for his proposed wall, including one with blue steel on top. All eight models are between 18 to 30 feet high and 30 feet long. Four are made of concrete, while the others are made of alternate materials.
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While viewing the designs, Trump said he has a strong preference for a border wall that would allow law enforcement to see through into Mexico.
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"You have to have see through. You have to know what's on the other side of the wall. You could be two feet away from a criminal cartel and not even know they're there," he said.
In some brief remarks to reporters, Trump painted a curious picture of Mexican immigrants looking to cross the border. He said the tallest walls possible are needed because, "these are like professional mountain climbers, these are incredible climbers."
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The president resumed his feud with the state of California, criticizing Gov. Jerry Brown, its immigrant protections and the state's tax system.
"I think Governor Brown's done a very poor job running California. They have the highest taxes in the United States. The place is totally out of control. You have sanctuary cities where you have criminals living in sanctuary cities, and then the mayor of Oakland goes out and notifies when ICE is going in to pick them up," he said.
RELATED: Trump blasts Gov. Brown in California visit
President Trump lands in San Diego to see border wall prototypes
Building a wall along the border with Mexico was a central campaign issue for Trump, who said the wall will help fight drug trafficking and unauthorized immigration.
A rally of wall supporters prompted heavy security to make sure there are no clashes between those for and against the plan.
"We are coming out here to support our president and show him that there are a lot of California Trump supporters here, and we are all coming together and banding together to let him know that we're here for him," said San Diego resident Amy Sutton.
WATCH: Protesters await President Trump's arrival in San Diego
Protesters await Trump's arrival in San Diego
"I came out because we're a country of immigrants and Trump is against everything our country stands for," said Diane McNelly, who was positioned with other demonstrators along what was believed to be part of the president's motorcade route. "He's a racist, misogynistic, and he's totally unqualified and inept. It just makes me sad to see it."
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Although the Trump supporters and a few protesters shouted at each other, there were no serious clashes and the groups dispersed soon after the presidential motorcade passed.
Trump supporters, protesters gather for president's CA visit
Following his tour of the prototypes, Trump spoke to members of the military at Marine Corps Air Station Miramar.
"For too long, the men and women of the armed forces have been asked to do more with less," Trump said, adding that military members are "our most brilliant weapons" and deserve a raise.
Later Tuesday, a protest organized by the political group Union Del Barrio was expected to take place in Beverly Hills ahead of Trump's arrival at the fundraiser, where donors will pay $250,000 to attend.