Michael BloombergSHANNON STAPLETON/REUTERS/NewscomNew York City's biggest fan of "stop and frisk" has registered (re-registered, really) as a member of the Democratic Party.

No, not President Donald Trump. Former New York City Mayor Michael Bloomberg on Wednesday formally registered as a Democrat, a gesture that may presage a presidential run in 2020. Bloomberg documented his registration with an Instagram picture that included the following statement:

At key points in U.S. history, one of the two parties has served as a bulwark against those who threaten our Constitution. Two years ago at the Democratic Convention, I warned of those threats. Today, I have re-registered as a Democrat—I had been a member for most of my life—because we need Democrats to provide the checks and balance our nation so badly needs.

I actually laughed when I read the statement. The very idea that Bloomberg is a protector of our constitutional rights is comical. Bloomberg is the archetype of the "Nanny knows best" authoritarian who will happily deprive you of your rights and your freedoms in the name of protecting you. In Reason's 45th anniversary issue, we highlighted him as one of our "45 Enemies of Freedom."

How does Bloomberg hate your freedoms? Let us count the ways.

He supports unconstitutional searches. Trump has been criticized, rightly, for recommending "stop and frisk" searches to fight crime in Chicago. Such stops are supposed to be based on reasonable suspicion of criminal activity but frequently are not, which according to the Supreme Court makes them inconsistent with the Fourth Amendment.

As mayor, Bloomberg enthusiastically defended the New York Police Department's stop-and-frisk program, which at its peak stopped nine innocent people for every individual who was arrested or issued a summons. Most of those stops included pat-downs, which were supposedly based on reasonable suspicion that the targets were armed yet failed to find weapons 98 percent of the time. In 2013, a federal judge ruled that the NYPD's stop-and-frisk practices were unconstitutional, and the current mayor, Bill de Blasio, declined to appeal that decision. Although the program's supporters insisted it was crucial in preventing violence, crime rates continued to fall in the Big Apple as stop-and-frisk encounters dropped dramatically.

Last month Bloomberg defended stop-and-frisk practices in an interview with The New York Times, arguing that Democratic voters agree with him. "I think people, the voters, want low crime," he said. "They don't want kids to kill each other." The comment was a non sequitur, since stop and frisk is demonstrably not what is stopping kids from killing each other.

Reason coverReasonHe supports secret surveillance of citizens. Under Bloomberg, the NYPD engaged in extensive and secretive surveillance of Muslim citizens in an effort to track down potential terrorists. The NYPD and the city were sued after the Associated Press revealed that the police had built an extensive surveillance program that was snooping on Muslim groups, students, and businesses, monitoring them even when there was no evidence that they were planning any sort of terrorist activity.

Muslim citizens and privacy activists were outraged when the extent of the snooping was revealed. But Bloomberg has defended it, saying that it "saved lives," although the police later admitted it had not generated a single terrorism investigation. The A.P. reporters won Pulitzers for exposing the snooping.

He wants to limit Second Amendment rights. Bloomberg is spending millions to promote "universal gun background checks," a popular policy that he says will stop bad people from getting guns. But the policy, which requires a background check for all gun transfers, even when they do not involve federally licensed dealers, imposes a substantial burden on innocent people who pose no threat to public safety.

After analyzing one proposal supported by Bloomberg, gun policy expert Dave Kopel warned that "the bill would felonize a couple who are not legally married, but who share firearms at a target range," "the friend who lends a gun to a stalking victim for a few days," and "a member of the Army Reserve who is summoned to overseas deployment, and who stored personal guns with a sibling or a trusted friend."

If background checks worked as intended, they would stop millions of harmless people from buying guns. Federal law prohibits gun ownership by anyone who consumes cannabis, for instance, or who was ever convicted of a felony, violent or not. Meanwhile, of course, violent criminals could always buy guns on the black market.

He wants to control what you eat and drink. Bloomberg has a seemingly bottomless appetite for controlling what you consume. Most famously, he attempted to institute a ban in New York that would have stopped the sale of sugary drinks in sizes larger than 16 ounces. He failed, but he learned little from the experience, insisting, "We have a responsibility as human beings to do something, to save each other, to save the lives of ourselves, our families, our friends, and all of the rest of the people that live on God's planet."

Bloomberg also pushed for a reduction in the salt content of packaged and prepared food in New York City. As with sugary drinks, he said the mandate would protect our health. Yet the science does not, in fact, indicate that there's a widespread problem with the amount of salt in our food. Most Americans are not eating too much salt.

Bloomberg's impulse to turn medical studies into government edicts is a problem not just because it violates our personal freedoms but because our understanding of health science changes over time. The federal government regularly gives out what turns out to be bad dietary advice.

He wants to control what you smoke. It shouldn't come as surprise that a man who wants to keep you from eating sugar and salt also wants to stop you from smoking. He supports just about every government effort to meddle with people' smoking habits: smoking bans; higher cigarette taxes; restrictions on tobacco advertising; and bans on flavored tobacco products. Toward the end of his final term, New York City raised the minimum purchase age for cigarettes from 18 to 21. Not only has Bloomberg attacked smoking, but he wants to treat tobacco-free e-cigarettes as though they're the same as conventional cigarettes, even though they are far less hazardous.

The upshot of Bloomberg's efforts to make it harder for New Yorkers to smoke has been a massive cigarette black market. One result of that was the deadly 2014 encounter between the NYPD and Eric Garner, who essentially was choked to death for selling loose, untaxed cigarettes.

Leaving office hasn't stopped Bloomberg from trying to control what you do with your body. He contributed $1.8 million to the successful effort to ban the sale of flavored tobacco products and e-cigarettes in San Francisco.

Bloomberg is also down on marijuana legalization, calling the very idea of medical marijuana one of the "great hoaxes of all time" as recently as 2015. Under Bloomberg's rule as mayor, the NYPD continued to arrest people for marijuana possession even after the state changed the law to make it a citable offense like a traffic violation.

Below, Reason TV bid Bloomberg a not-very-fond farewell when his three terms as mayor ended: