Editor's note: Ruben Navarrette Jr. is a CNN.com contributor and a nationally syndicated columnist.
San Diego, California (CNN) -- What is it about immigration? It brings out the best in America. And yet, talking about it brings out the worst in many Americans. The United States is becoming withdrawn and bitter, and the national mood is becoming uglier.
It's nothing new. We live in a country that has -- for more than 220 years -- held the curious distinction of being a nation of immigrants that doesn't like immigrants. Our national motto isn't really "e pluribus unum." It's more like: "There goes the neighborhood."
Whether they come legally, illegally, or with a letter of reference from the Queen of England, every batch of foreign arrivals to these shores is instantly considered inferior to those who came before. It helps Americans feel better about their lot. Whereas they have always tended to think of immigrants as less than them, nowadays some go for broke and consider them less than human.
And, in the 21st century, it's open season on immigrants from Mexico and Latin America. I don't mean that literally. But unfortunately, these days, some folks might take it that way.
In Racine, Wisconsin, the owner of a local gas station began selling a bumper sticker that read: "Illegal Immigrant Hunting Permit." He apparently didn't find it the least bit offensive, but local immigrant activist Maria Morales did.
"It's clearly hate," the grandmother told a local TV reporter. "So people will see this and they'll say, 'Hey, we have the right to kill them.' "
Morales planned a protest at the gas station, but the owner backed down and pulled the stickers from the shelves.
End of story? No such luck. A few days later, someone went to Morales' house and lit a fire outside her bedroom window. A police officer called to the scene put out the blaze, and the Racine Police Department is investigating the incident, which some local residents are calling a hate crime.
Morales does not believe in coincidences.
"I thought right away, 'It's that darn sticker that I'm fighting against,' " she told the TV reporter.
Morales said a few days before the fire she got an anonymous letter in the mail accusing her of violating the First Amendment and attacking her crusade to ban the bumper sticker. It was signed, "Uncle Freaking Sammy."
The First Amendment only prohibits government from making laws infringing upon individuals' free speech rights. And, as long as we're talking about rights, if the person who created that bumper sticker had the right to make it, and the store had the right to sell it, then Morales had the right to be offended by it. But no one has the right to commit an act of violence or attempt to destroy private property as an act of retaliation or intimidation.
Meanwhile, at the Newark Liberty International Airport, what you might call an arm of "Uncle Freaking Sammy" has also, according to an internal federal report, been improperly hunting immigrants.
I'm not talking about the U.S. Border Patrol or Immigration and Customs Enforcement. That would make too much sense. After all, that sort of thing is practically in the job description of those agencies.
The immigrant hunters in question worked for the Transportation Security Administration. Their specific job title is: Behavior Detection Officers. These officers are trained to detect suspicious behavior and they have the authority to pull air travelers aside for additional questioning. They're supposed to use that specialized training and extra authority to look for terrorists who might appear nervous or jittery.
Instead, according to TSA officials who blew the whistle and additional documents obtained by the Newark, New Jersey, newspaper, The Star-Ledger, some of these behavior detection officers would regularly single out passengers who were Mexican or Dominican in order to check their visas and passports.
The internal TSA report that looked at all this (the Star-Ledger said it was dated January 2010), found that those passengers who, once pulled aside, didn't have their paperwork in order would be questioned again and have their bags re-checked. Then they'd be sent along to immigration authorities, supposedly because of suspicious behavior.
According to one whistle-blower, TSA supervisors knew about and condoned the practice; in fact, the officers were jokingly called "the great Mexican hunters."
The TSA said in a statement that it does not profile passengers based on race, ethnicity or religion and that, in this case, "TSA's policies were overstepped."
Interestingly enough, no attempt was made to single out passengers with invalid paperwork who might have been Irish, Swedish, Russian or Belgian. Light skin has its privileges.
And not just at the Newark airport. All over the country, law enforcement agencies are being empowered to profile Latinos as a shortcut way of looking for illegal immigrants. Arizona sparked a disturbing national trend when it passed SB 1070, deputizing local and state police to enforce federal immigration laws. According to the National Immigration Forum, an immigration advocacy group, in the past year, lawmakers in at least 20 states -- most recently, Georgia and Alabama -- have tried to follow Arizona's lead.
What has happened to my country? Our nation's soul has been coarsened by the immigration debate. Americans now say, do and believe the most cruel and outrageous things when it comes to immigrants -- both legal and illegal, and especially those with dark skin who speak Spanish. Anything goes. There is no shame and no punishment.
Is this the America that nativists are so desperate to preserve? If so, is it even worth the effort?
The opinions expressed in this commentary are solely those of Ruben Navarrette Jr.