Remember that time that Republican presidential nominee talked about he was the "law and order" candidate who alone could take back the night from the non-existent legions of roving crime gangs and punks not seen since the 1979 movie The Warriors? Well, he's wrong. There is no big crime trend happening.

Still boggled at the notion of crime as an electoral issue (chart ends at 2013, but no significant change since) pic.twitter.com/enJgjCEraB — Paul Krugman (@paulkrugman) July 23, 2016

Now that's an interesting point Nobel laureate Paul Krugman makes and it's basically correct. There have been some fluctuations in property and violent crime since 2013 according to government data, but not really so much.

Which leads Tyler Cowen of George Mason University and the Mercatus Center to ask a sharp rejoinder question:

Am confused that for the Left "guns" are a big issue, but apparently "crime" is not, https://t.co/fQU3quSles, #help — tylercowen (@tylercowen) July 23, 2016

This is not just a great gotcha on the eve of the Democratic National Convention, which starts on Monday in Philadelphia and will be chock full of apocalyptic speechifying about a non-existent "epidemic" of gun violence. It's an understated guide to just how politicized things get, especially around convention seasons. Each party will exploit similar issues while attacking the other for being out of touch with reality.

Despite recent mass shootings such Orlando and San Bernardino, which targeted specific people for ideological reasons, or Dallas, where cops were killed, violence is basically half of what it was 20 years ago. This is not a small reduction:

In 1995, for instance, the violent crime rate (which includes murder, rape, robbery, and aggravated assault) per 100,000 inhabitants was 684.5. In 2014, it stood at 365.5. For murder and non-negligent manslaughter, the rate was 8.2 and 4.5 in 2014. These trends also show up in other violent crimes too.

When it comes to guns specifically, the same general pattern holds, with massive reductions in rates from 20 years ago:

The gun murder rate in 1993 was 7.0 per 100,000, according to the Centers for Disease Control and Prevention's (CDC) National Center for Injury Prevention and Control. (Those reports rely on death certificate reporting, and they tend to show higher numbers than the FBI's Uniform Crime Reporting program, though both trend the same.) In 2000 the gun murder rate per 100,000 was 3.8. By 2013, the rate was even lower, at 3.5, though there was a slight upswing in the mid-00s.

This has all been happening as the individual right bear arms has been expanded by numerous state and local laws as well as Supreme Court rulings. There are more guns in circulation than there are Americans, and we are able to carry them legally in more circumstances than at any point in the past 30 or more years. While there are reasons to believe that the gun-related homicide may bump up this year (especially in cities with relatively strict gun control, such as Chicago), there is no reason to believe that either crime or gun offenses are about to bounce back to where they were 20, 30, or 40 years ago. And as James Alan Fox, the Northeastern University criminologist who has been tracking mass shootings since the 1980s, reminded us after the gruesome San Bernardino shooting last December, "You're not about to die in a mass shooting." While there are variations in fatalities in various years, he stresses that the number of incidents in which four or more people are wounded is not getting bigger:

As for the risk of mass shooting, it is also something we need to keep in perspective. About 100 Americans, on average, are killed each year in mass shootings — out of a population of over 300 million. I kind of like those odds.

Liberals and Democrats think Donald Trump's invocation of a fake crime wave is simply a means by which the billionaire hopes to scare people into accepting him as a savior. They're right to point to a lack of evidence that crime is getting out of hand.

And when Hillary Clinton and Democrats this upcoming week start talking about the need to stop the "epidemic" of gun violence by declaring an unnecessary and sure-to-be-ineffective war on guns, it will be right to point out that they are wrong on that score, too.