EL PASO — President Trump is to arrive here on Monday for a rally to champion his border wall with Mexico even as a demonstration is planned by angry residents and Democratic lawmakers who denounce his claim that walls reduce violent crime.
Mr. Trump’s rally, his first since an acrimonious debate over funding of the wall shut down the government, comes as negotiations in Washington to head off another shutdown are in danger of collapse. His words could inflame the national debate over immigration, which is already a powerful rallying cry for Democrats hoping to challenge Mr. Trump in 2020.
Among those potential challengers is Beto O’Rourke, the rising Democratic star and former congressman from El Paso. In a bit of political theater that could be a foretaste of the 2020 campaign, Mr. O’Rourke will speak at a rally less than a mile away from the El Paso County Coliseum, where Mr. Trump is scheduled to address 6,000 supporters.
The president’s choice of El Paso to make his argument is curious on several grounds. Violent crime actually declined for years in this vibrant immigrant city across the river from Ciudad Juárez, Mexico, before the Army Corps of Engineers began building a fence in 2008. It rose during the two years before and after the barrier was constructed.
[Sign up for Crossing the Border, a limited-run newsletter about life where the United States and Mexico meet.]
A Democratic stronghold in an otherwise Republican state, El Paso has long been one of the safer cities of its size in the United States — a trend that local law enforcement officials attribute to the residents and community policing, not to the border fence.
Still, if Mr. Trump wants to force the debate with Democrats, he could hardly have chosen a better place. The presence of Mr. O’Rourke, who represented the city in Congress before he gave up his House seat to run unsuccessfully for the Senate last year, guarantees the president the kind of confrontation he relishes, even if the two men will not come face-to-face.
The president has insisted that El Paso was an example of why a wall is necessary.
“The border city of El Paso, Texas, used to have extremely high rates of violent crime — one of the highest in the country,” Mr. Trump claimed last week during his State of the Union address. “Now, with a powerful barrier in place, El Paso is one of our safest cities.”
Mr. O’Rourke debunked that claim on Friday in a lengthy post on the website Medium, in which he also attempted to set out an alternative blueprint for overhauling the nation’s immigration laws. El Paso’s success, he said, repudiated Mr. Trump’s call for a border wall.
“He will promise a wall and repeat his lies about the dangers that immigrants pose,” Mr. O’Rourke said of the president.
Mr. O’Rourke has spotlighted his heavily Latino hometown on Facebook and on other social media sites as an example of what works in immigration policy. He plans to join a “March for Truth” on Monday that will be a counterpoint to Mr. Trump’s “Make America Great Again” rally.
“We will welcome the president to one of the safest cities in the United States,” he wrote on Medium. “Safe not because of walls, and not in spite of the fact that we are a city of immigrants. Safe because we are a city of immigrants and because we treat each other with dignity and respect.”
Mr. Trump got the idea to focus on El Paso from an exchange with the Texas attorney general, Ken Paxton, who told him the wall drastically reduced the city’s crime rate and therefore served as a persuasive argument for building a wall along more of the southwestern border.
“After that fence went up and separated Juárez, which still has an extremely high crime rate, the crime rates in El Paso are now some of the lowest in the country,” Mr. Paxton said. “So we know it works.”
While it is true that Juárez has a much higher crime rate than El Paso — and while the fence did cut down on illegal crossings — the rest of his statement is, at best, highly misleading.
The El Paso Times, which analyzed three decades of statistics from the F.B.I. and local police, found that crime peaked in 1993, with more than 6,500 violent crimes recorded. It then dropped by 34 percent over the next 13 years.
The crime rate then increased by 17 percent from 2006 to 2011. Construction of the wall began in 2008, under President George W. Bush, and was completed in mid-2009, during the Obama administration. Crime has ebbed and flowed within a fairly narrow band since then.
Local officials, including Mayor Dee Margo, a Republican, have spoken out against Mr. Trump’s claims. Representative Veronica Escobar, a Democrat who recently won Mr. O’Rourke’s former seat, has demanded that the president apologize and meet with migrant families seeking asylum in the United States.
Among lawmakers who represent border districts, there is remarkably little support for a wall, and Democrats in Washington have stuck to their refusal to give Mr. Trump the $5.7 billion he is requesting for it. The latest numbers floated by Democrats in their negotiations with their Republican counterparts are between $1.3 billion and $2 billion.
Yet Mr. Trump has been undeterred. During his State of the Union address, he repeated grisly stories of violent crimes committed by illegal immigrants — never mind that the crime rate among immigrants is no higher than among native-born residents. He said a wall would stem the flow of deadly opioids and other illicit drugs into the United States — another dubious assertion, given that most drugs arrive at legal ports of entry.
Mr. Trump’s aides are trying to build a momentum after what they believe was a speech well received by his political base. Unlike some of his predecessors, the president did not immediately leave on a road trip to sell the messages in the address. But he has been eager to return to rallies, which energize him and filled up his calendar before the midterm elections.