Mike Coffman, the conservative Republican mayor of Aurora, Colo., had a message for former President Donald J. Trump before the Republican nominee for the White House came on Friday to a city he has repeatedly painted as having been taken over by vicious migrant street thugs.

The visit, Mr. Coffman said in a statement to The Times, “is an opportunity to show him and the nation that Aurora is a considerably safe city — not a city overrun by Venezuelan gangs. My public offer to show him our community and meet with our police chief for a briefing still stands.”

It is not a message likely to get through.

In the closing weeks of Mr. Trump’s campaign, his efforts to demonize immigrants, whether they are from Venezuela, Haiti or elsewhere, have gotten ever more lurid — and more impervious to the facts, even those provided by Republican allies such as Mr. Coffman. Last month, the former president began portraying Aurora, a sprawling suburb of Denver, population 404,219, as “a war zone” overrun by a violent Venezuelan street gang, Tren de Aragua.

Despite the entreaties of Aurora city officials in both parties to stay away, Mr. Trump is taking his case to Aurora itself on Friday. He will head there for an afternoon rally at the Gaylord Rockies Resort & Convention Center, a location that is decidedly not overrun by Venezuelan gangs.