This November 4, 2014 file photo shows a man as he holds up a sign for Ballot Initiative #71, the legalization of marijuana in Washington, DC. Campaigners vowed December 12, 2014 to pursue the legalization of marijuana in Washington, after language intended to prohibit pot in the US capital slipped through Congress. Riders to the $1.1 trillion federal spending bill approved Thursday by the House of Representatives bars the District of Columbia from enacting or implementing laws to legalize cannabis. (Brendan Smialowski/AFP/Getty Images)

Andy Harris, a Republican, represents Maryland’s 1st Congressional District in the House, where Joe Pitts, a Republican, represents Pennsylvania’s 16th Congressional District.

Many have asked why Republican legislators who profess respect for self-government and democracy would step in to overrule D.C. residents who voted to legalize recreational marijuana use in the city. We would like to answer that question head-on. Simply put, we believe that Congress must defend the federal government and the U.S. Constitution by preventing marijuana legalization from moving forward in the District.

Federal policy on marijuana is neither arbitrary nor set in stone. Proper procedures exist for changing the way that marijuana is regulated in the United States, but a ballot initiative in the federal district is not one of them. If the city were allowed to proceed, it would create legal chaos.

The classification of marijuana as a Schedule I controlled substance was made through a legal and scientific process established by Congress and administered by the Food and Drug Administration and the Drug Enforcement Agency. This classification means that the drug has a high potential for abuse, has no accepted medical use and cannot be used safely even under medical supervision.

Marijuana use is far from benign, and the effect the drug has on users can ripple through a lifetime and touch both their families and society at large.

Many studies have shown that use of marijuana can have a wide range of negative effects on an individual’s brain, body and behavior. This includes short- and long-term effects on functions such as brain development, memory and cognition, motivation and lung health. Persistent marijuana users have shown a significant drop in IQ between childhood and midlife.

Marijuana is the illicit drug most frequently found to be a factor in car accidents, including fatal ones. Both emergency department visits involving marijuana and treatment admissions for abuse have increased in recent years. In 2011, according to the National Institute on Drug Abuse (NIDA), there were 128,857 emergency room visits related to marijuana use, about the same as for heroin use and almost double the number of marijuana ER visits in 2004 (65,699).

Legalization in some jurisdictions has led to increased marijuana use by teenagers. According to officials in Nebraska, areas of the state that border Colorado, where recreational marijuana is legal, have seen an increase in the number of teens ticketed for possession of marijuana and a spike in the drug’s potency. The American Academy of Child and Adolescent Psychiatry, in a statement approved just this year, maintains that: “Marijuana use is not benign, and adolescents are especially vulnerable to its many known adverse effects.” The group opposes efforts to legalize the drug even for adult use.

There is much we still don’t know. NIDA is doing important research into the impact of marijuana use. We need more investigation into the health effects of recreational consumption, its effect on teen educational achievement and the economic impact of using the drug. We also need to look closely into chemical components of marijuana, such as THC and CBD, that could have medical indications and figure out ways to avoid the negative effects of smoking or ingesting marijuana.

The FDA and DEA have a process for analyzing such studies and approving controlled substances. We do not let any other substance become approved by ballot initiative. Every drug must be subject to the same strict scrutiny.

Legalizing marijuana in the District is a recipe for legal chaos. There are 26 separate law enforcement agencies in the city. Twenty-five of them answer only to the federal government. If the city proceeded with legalization, whether an individual is arrested for marijuana possession could end up hinging on whether the arresting officer works for the Metropolitan Police Department or, say, the National Park Service. Individuals possessing an amount of marijuana legal by District law could find themselves arrested and prosecuted after they walk into a federal building or step into a federal park.

We believe every state should respect federal law and take caution prior to legalizing marijuana. Unlike in the states, though, Congress has a direct responsibility under Article I, Section 8, of the Constitution, for policy in the District. This does not mean we need to micromanage. The people of the District should have a local government that is tailored to their needs. But when their wishes clearly conflict with federal law, Congress’s will must be preeminent.