How does personal drug possession affect interstate commerce?
<p>According to the <a href="http://www.fda.gov/regulatoryinformation/legislation/ucm148726.htm" rel="nofollow noreferrer">Controlled Substance Act</a>:</p>

<blockquote>
  <p>§ 801. Congressional findings and declarations: controlled substances....</p>
  
  <p>...(3) A major portion of the traffic in controlled substances flows through interstate and foreign commerce. <strong>Incidents of the traffic which are not an integral part of the interstate or foreign flow, such as manufacture, local distribution, and possession, nonetheless have a substantial and direct effect upon interstate commerce because</strong> -</p>
  
  <p>(A) after manufacture, many controlled substances are transported in interstate commerce,</p>
  
  <p>(B) controlled substances distributed locally usually have been transported in interstate commerce immediately before their distribution, and</p>
  
  <p>(C) controlled substances possessed commonly flow through interstate commerce immediately prior to such possession.</p>
  
  <p>(4) <strong>Local distribution and possession of controlled substances contribute to swelling the interstate traffic in such substances.</strong></p>
  
  <p>(5) Controlled substances manufactured and distributed intrastate cannot be differentiated from controlled substances manufactured and distributed interstate. Thus, it is not feasible to distinguish, in terms of controls, between controlled substances manufactured and distributed interstate and controlled substances manufactured and distributed intrastate.</p>
  
  <p>(6) Federal control of the intrastate incidents of the traffic in controlled substances is essential to the effective control of the interstate incidents of such traffic.</p>
  
  <p>(7) The United States is a party to the Single Convention on Narcotic Drugs, 1961, and other international conventions designed to establish effective control over international and domestic traffic in controlled substances.</p>
</blockquote>

<p>From what I understand, this means that because of <a href="https://en.m.wikipedia.org/wiki/Commerce_Clause" rel="nofollow noreferrer">the Commerce Clause</a> of the Constitution, which grants Congress the power:</p>

<blockquote>
  <p>To regulate Commerce with foreign Nations, and among the several States, and with the Indian Tribes.</p>
</blockquote>

<p>...Controlled Substances may not be exchanged through interstate commerce. Also, because it is impossible to determine whether drugs produced for intrastate commerce are also crossing state lines, then:</p>

<blockquote>
  <p>(5)...<strong>it is not feasible to distinguish, in terms of controls, between controlled substances manufactured and distributed interstate and controlled substances manufactured and distributed intrastate.</strong></p>
  
  <p>(6) <strong>Federal control of the intrastate incidents of the traffic in controlled substances is essential to the effective control of the interstate incidents of such traffic.</strong></p>
</blockquote>

<p>Therefore, no intrastate commerce is allowed. However, I don't understand how possession or manufacturing of drugs for personal consumption is covered in the Commerce Clause.</p>

<p>For example, let's say I wish to grow one cannabis plant for personal consumption. In what way does this affect the cannabis market in other states so that Congress has the power to prohibit it?</p>

<p>To pick up on your comment 'Does this mean if I wish to build a chair for personal use, then since trade of chairs exists between states, Congress has the authority to outlaw possession or manufacturing of chairs?': Yes.</p>

<p>For example, the US Congress can legislate to prohibit a farmer from growing wheat for use on his own farm, on the basis that there is interstate trade in wheat and therefore the Commerce Clause permits Congress to regulate the growing of wheat: <em>Wickard v Filburn</em> (1942) 317 US 111.</p>

<p>If you grow marijuana, or build a chair, or whatever, you conceivably affect the number of marijuanas, chairs, etc that are traded between states. Therefore you affect interstate commerce. Therefore the US Congress can regulate you. The fact that your marijuana or your chair or your what is trivial in the scheme of the national economy is irrelevant if the aggregation of all regulated marijuana, chairs or wheat is significant: 317 US 111, 127-128.</p>

<p>If the law didn't prohibit possession of marijuana absolutely but instead prohibited, say, the carrying of marijuana in schools, then the US Congress might have trouble relying on the Commerce Clause: see <em>United States v Lopez</em> (1995) 514 US 549 and replace 'marijuana' with 'handguns' (OK the marijuana/handgun analogy is bad but hopefully this illustrates that there are at least some limits on Congress' power -- it's not just 'any physical object that relates whatsoever to interstate trade therefore unfettered federal legislative power').</p>

<p>The relevant case is <a href="https://supreme.justia.com/cases/federal/us/545/1/" rel="noreferrer">Gonzales v. Raich, 545 U.S. 1 (2005)</a>.</p>
<blockquote>
<p>Congress’ Commerce Clause authority includes the power to prohibit the local cultivation and use of marijuana in compliance with California law.</p>
</blockquote>
<p>The court relied heavily on Wickard, and distinguished the case from Lopez:</p>
<blockquote>
<p>The similarities between this case and Wickard are striking. In both cases, the regulation is squarely within Congress’ commerce power because production of the commodity meant for home consumption, be it wheat or marijuana, has a substantial effect on supply and demand in the national market for that commodity.</p>
<p>[...]</p>
<p>The case comes down to the claim that a locally cultivated product that is used domestically rather than sold on the open market is not subject to federal regulation. Given the CSA’s findings and the undisputed magnitude of the commercial market for marijuana, Wickard and its progeny foreclose that claim.</p>
</blockquote>

<p>Another relevant and recent case is <a href="https://www.supremecourt.gov/opinions/15pdf/14-6166_o7jp.pdf" rel="nofollow noreferrer"><em>Taylor v. United States</em></a>, 579 U.S. ____, Case No. 14-6166 (June 20, 2016) (with only one justice dissenting). The official syllabus (citations to slip opinion omitted) states:</p>

<blockquote>
  <p>Petitioner Taylor was indicted under the Hobbs Act on two counts of
  affecting commerce or attempting to do so through robbery for his
  participation in two home invasions targeting marijuana dealers. In
  both cases, Taylor and other gang members broke into the homes,
  confronted the residents, demanded the location of drugs and money,
  found neither, and left relatively empty handed.</p>
  
  <p>Taylor’s trial resulted in a hung jury. At his retrial, the Government
  urged the trial court to preclude Taylor from offering evidence that
  the drug dealers he targeted dealt only in locally-grown marijuana.
  The trial court excluded that evidence and Taylor was convicted on
  both counts. The Fourth Circuit affirmed, holding that, given the
  aggregate effect of drug dealing on interstate commerce, the
  Government needed only to prove that Taylor robbed or attempted to rob
  a drug dealer of drugs or drug proceeds to satisfy the commerce
  element.</p>
  
  <p>Held:</p>
  
  <ol>
  <li>The prosecution in a Hobbs Act robbery case satisfies the Act’s commerce element if it shows that the defendant robbed or attempted to
  rob a drug dealer of drugs or drug proceeds.</li>
  </ol>
  
  <p>(a) The language of the Hobbs Act is unmistakably broad and reaches
  any obstruction, delay, or other effect on commerce, 18 U. S. C.
  §1951(a), “over which the United States has jurisdiction,”
  §1951(b)(3). See United States v. Culbert, 435 U. S. 371, 373. </p>
  
  <p>(b) Under its commerce power, this Court has held, Congress may
  regulate, among other things, activities that have a substantial
  aggregate effect on interstate commerce, see Wickard v. Filburn, 317
  U. S. 111, 125. This includes “purely local activities that are part
  of an economic ‘class of activities’ that have a substantial effect on
  interstate commerce,” Gonzales v. Raich, 545 U. S. 1, 17, so long as
  those activities are economic in nature. See United States v.
  Morrison, 529 U. S. 598, 613. One such “class of activities” is the
  production, possession, and distribution of controlled substances. 545
  U. S., at 22. Grafting the holding in Raich onto the Hobbs Act’s
  commerce element, it follows that a robber who affects even the
  intrastate sale of marijuana affects commerce over which the United
  States has jurisdiction.</p>
  
  <p>(c) In arguing that Raich should be distinguished because the
  Controlled Substances Act lacks the Hobbs Act’s additional commerce
  element, Taylor confuses the standard of proof with the meaning of the
  element that must be proved. The meaning of the Hobbs Act’s commerce
  element is a question of law, which, Raich establishes, includes
  purely intrastate drug production and sale. Applying, without
  expanding, Raich’s interpretation of the scope of Congress’s Commerce
  Clause power, if the Government proves beyond a reasonable doubt that
  a robber targeted a marijuana dealer’s drugs or illegal proceeds, the
  Government has proved beyond a reasonable doubt that commerce over
  which the United States has jurisdiction was affected.</p>
  
  <ol start="2">
  <li>Here, the Government met its burden by introducing evidence that Taylor’s gang intentionally targeted drug dealers to obtain drugs and
  drug proceeds. That evidence included information that the gang
  members targeted the victims because of their drug dealing activities,
  as well as explicit statements made during the course of the robberies
  that revealed their belief that drugs and money were present. Such
  proof is sufficient to meet the Hobbs Act’s commerce element.</li>
  </ol>
  
  <p>754 F. 3d 217, affirmed.</p>
</blockquote>

constitutional-law commerce medical-marijuana