This week at a rally in Nashville, President Trump did a little call-and-response with the crowd. "They're not human beings," he said. "And this is why we call the bloodthirsty MS-13 gang members exactly the name that I used last week. What was the name?" "ANIMALS!" the crowd shouted lustily in response. Everyone was having a great time, which is not exactly the mood you're usually in when expressing your genuine dismay at terrible crimes that have been committed.

But "animals" has become the latest conservative shibboleth, a marker of identity for which there is extra enthusiasm since it can be used to Trigger the Libs. It all started when in a White House meeting the president rambled on about undocumented immigrants being animals, and depending on whom you believe he might or might not have been talking specifically about MS-13. Liberals pointed out that dehumanizing language like that has many times through history been deployed as a prelude to campaigns of mass murder, and furthermore Trump is doing what he has done many times: used an individual crime to stir up fear and hatred of an entire class of people.

The response to that was predictable. At that rally, Trump called Nancy Pelosi an "MS-13 lover," saying, "She loves MS-13. Can you imagine?" You'll have to imagine, because it's a lie as repugnant as any Trump has told. It's also perfectly in line with a long GOP tradition, whether it was Richard Nixon campaigning on "law and order" or Ronald Reagan telling of how frustrating it was to be behind a "strapping young buck" buying steaks at the grocery store with food stamps. But the strategy reached its apogee in 1988.

If you're a young person today, what you know about George H.W. Bush is probably that he's a kindly old man who gets lots of respect from both Republicans and Democrats, his presidency a brief period of reasonableness and relative calm. You may be less aware of the fact that he reached the Oval Office with a scorched-earth campaign against his opponent Michael Dukakis, one that continues to echo today.

The symbolic centerpiece of that campaign was the story of Willie Horton — though his name was William, which is how he was referred to in news reports prior to the 1992 campaign; where "Willie" came from is unclear, though you may have your suspicions. Horton, an inmate in Massachusetts, escaped while on a prison furlough, then went on to rape a woman and assault her fiance. The furlough program was founded under Dukakis' predecessor, but the facts of the case didn't matter a bit.

What mattered was the story's ability to tap into centuries' worth of racist hate and fear: a criminal black man, terrorizing a white woman while her man lay helpless to save her. Should Dukakis be elected, Republicans said, this would be our horrifying future, the prison doors flung open so a horde of merciless brutes could rampage across the land defiling our women and leaving our manhood shredded. "By the time we're finished," said Bush campaign manager Lee Atwater, "they're going to wonder whether Willie Horton is Dukakis' running mate."

The news media eagerly ran with the story, putting Horton's menacing mug shot up on television night after night. At one of the presidential debates, CNN's Bernard Shaw opened the proceedings by asking Dukakis this about his wife: "Governor, if Kitty Dukakis were raped and murdered, would you favor an irrevocable death penalty for the killer?" Journalists then eviscerated Dukakis for giving an insufficiently emotional response, since instead of pounding his lectern in rage he calmly explained why he opposed the death penalty.

Needless to say, furlough policies in the federal prison system were not exactly Bush's top priority once he was elected. But everyone understood that the Willie Horton story had nothing to do with the job the next president would actually do; it was about reaching down into the darkest depths of white voters' psyche and poking what was to be found there.

In one way, the new Republican obsession with MS-13 is more complex, because it does have a connection to policy in that it serves as an excuse for a crackdown on immigrants. But like Willie Horton, its primary use is to promote racist fears. That's what Ed Gillespie, the Republican nominee for governor in Virginia last November, was hoping for when he aired a series of ads trying to tie MS-13 to his Democratic opponent. "MS-13 is a menace," one said. "Yet Ralph Northam voted in favor of sanctuary cities that let dangerous illegal immigrants back on the street, increasing the threat of MS-13."

For the record, there are no sanctuary cities in Virginia. And Gillespie failed, losing the election by 9 points. But Republicans aren't done talking about MS-13 or using the immigration issue to show they're the toughest and meanest candidates in the primary field. A recent analysis by USA Today showed that immigration has been mentioned more often than any other policy issue in the television ads of Republicans running for Congress this year (for the Democrats it was health care).

Is MS-13 a problem in some places? Sure. But there are many more serious problems that don't get a fraction of the attention from Republicans that MS-13 does. And you can bet that President Trump, who likes nothing more than telling lurid stories of violence to drum up hatred against those who are not white and native-born, will keep on talking about them.