On Tuesday in front of Congress, President Trump announced the launch of a new office to track crimes committed by unauthorized immigrants. It will issue quarterly reports “studying the effects of the victimization by criminal aliens present in the United States.” Democrats in the chamber audibly groaned.

Trump went on to recognize the family members of three victims of murders by undocumented immigrants–two were the wives of murdered cops, and the other was a father whose son was murdered by a gang member living illegally in the U.S.

That the President has this one wrong–the facts don’t justify this policy–is by now well known. As Business Insider reports, a 2009 study found that ‘broad reductions in violent crime […] are partially attributable to increases in immigration.’” That is, violent crime has gone down as immigration has gone up. Many other recent studies have come to similar conclusions.

Oh how easy it is to create an enemy of the state. 1. Identify a problem (crime). 2. Falsely imply that one group is disproportionality to blame (immigrants). 3. Highlight sensational cases (dead police officers). 4. Build an apparatus to punish the whole group.

But Democrats thundering at Trump from high up the moral mountaintop should recognize the pattern. That’s because they’ve long colluded, and often led the way in, inventing another enemy–those who’ve committed sex crimes.

Twenty years of robust studies confirm that those convicted of sex crimes have lower re-offense rates than almost any other group of ex-offenders. Upwards of 90 percent of new sex crimes are committed by someone who’s not on a sex offender registry.

No matter–since the mid-nineties, Democrats and Republicans have pitched in to build our dark labyrinth of sex offender laws. Those include not just public registries that list ex-offenders’ photos, addresses, and workplaces, but residency restrictions that ban them from living in all but a handful of homes. There are requirements that they send out (and foot the bill for) postcards when they move to a neighborhood, that place warning signs outside their homes, that set restrictions on what they can do on Halloween, and that ban them from places like parks, malls, and museums.

Our politicians seem at their most creative and collaborative when devising new rules to make the lives of this group, and often that of their families, miserable or impossible.

So Democratic New York Governor Andrew Cuomo and Democratic State Senator Jeff Klein compete over who can claim credit for banning sex offenders from playing Pokémon Go. Milwaukee Democratic alderman Tony Zielinkski sponsors a successful bill that bans registrants from living most anywhere in the city (which promptly spikes homelessness rates among those ex-offenders). Democratic New York Suffolk County Executive Steve Bellone and fellow county Democrats, over the objections of Republicans, ram through a program to funnel public money to an advocacy group that ratchets up the number of surprise visits to registrants’ homes. All justify their proposals with the false claim that these ex-offenders put their communities at high risk.

So once Democrats get a taste for resisting attempts to pin our problems on a defenseless target, maybe they’ll take a break to look in the mirror. Because they’ve been equal-opportunity offenders when it comes to beating up the scrawny kid on the playground who just looks like he deserves it.