Even though Memphis hasn’t suffered a terrorist attack, the city is using federal grants to fight crime, which might lead to the discovery of a terrorist suspect. Other cities are using federal money with similar programs.
How is this underlying logic any different from the run-of-the-mill interstate commerce interpretation from Washington? Remember Wickard v. Filburn? If a man growing wheat for his own use on his own land may be regulated by the federal government under the interstate commerce clause (because, by growing his own wheat, the farmer was diminishing the national market by a very small fraction), then any money sent by the federal government to any police department may constitute anti-terrorism funding. Such is the logic of unlimited government.