On the ground at Homestead's migrant detention facility

HOMESTEAD, Fla. — In the blaring sun, at least nine Democratic presidential candidates have stood on stepladders this week to peer into the migrant detention center here where approximately 2,600 teenagers are being held.

Why it matters: The immigration crisis is becoming the defining issue of the 2020 election — at least for now — as Democrats criticize not only the conditions in which these children are being held, but also the Trump administration's handling of young migrants who have come to the U.S. with their parents.

What it's like:

• Activists set up stepladders on Miami-Dade County property across the road from a building — on federal property — that houses 13- to 15-year-olds, hoping to catch a glimpse of and cheer on the detainees who occasionally emerge from the facility.
• A few told me that sometimes the kids — some wearing bright orange hats — wave back, but only when they’re with certain guards who are more lenient.
• Some of the 16- to 18-year-old detainees sleep in tents, though I'm told that all sleeping quarters are air-conditioned — a necessity in the Florida heat, which sent sweat streaming down the faces of everyone there while I visited.

People are there before and after candidates visit and the circus that follows them dies down. Many of those I talked to — some still in college, some as old as 80 — said things like: "It just felt bad not doing anything about this, so I had to come."

• 44-year-old Ali Wicks-Lim drove from Massachusetts to visit the facility with her 8- and 14-year-old daughters. "How could it be possible that it’s not OK for my children to witness what these other children are living?" she asked. "Shielding them and pretending it’s not happening will grow them into adults who don’t know enough to care."
• Those at the site said they hope the candidates continue to talk about Homestead even when Florida doesn't have the nation's attention thanks to the first Democratic presidential debates in Miami.

The backdrop: The facility is supposed to hold teenage migrants aged 13 to 18 for around 20 days at the most, per the New York Times, until they're sent to a "licensed shelter that has comfortable living accommodations and a full education program."

• But Democrats say they can't get a straight answer from the facility's personnel on just about anything — including how long some of these children have been detained.
• "No one can truly give me the average stay for the kids," said Florida Rep. Debbie Mucarsel-Powell, who's been granted access to tour the facilities. "I hear 44 [days], 60, 30."

The state of play: Earlier Friday, 2020 candidates Sen. Kamala Harris, Mayor Pete Buttigieg, Julián Castro, Sen. Kirsten Gillibrand, John Hickenlooper and Marianne Williamson visited the detention center. Sen. Elizabeth Warren, Sen. Amy Klobuchar and Beto O'Rourke visited earlier this week.

• While they were allowed inside the building into the processing area, none were allowed to tour the facilities.
• Harris and Gillibrand left after they gave brief remarks. Castro and Buttigieg had genuine exchanges with people, including Castro speaking with a Latina mom there with her children, who asked him "If something happens to me, what’s going to happen to my kids?"

What they're saying: "What the hell are they hiding?" asked Castro, who has visited Homestead several times, during his remarks. "We were stonewalled today by an administration and a private contractor who does not want us to see what's behind those walls."

• "Part of the strength of our nation is supposed to be that we have strong arms which will embrace or protect anyone facing harm," said Harris. "But that’s not what we see from this administration because this is an administration that prefers to beat people down rather than lift them up."
• Buttigieg said he asked about the sleeping conditions while briefly inside the building and was told that there are six children to a room, but for those sleeping in a "bay," there are more than 100 people in that room. "You and I paid for this place," he told the crowd. "What is being done in that building is being done in our country and with our money. ... Let’s make sure for certain this is America’s last-ever for-profit child prison."

Go deeper: America's only for-profit detention center for migrant children