Pretend you are a public defender (defense attorney). Your client is a resident of California. Last summer he was arrested in Yosemite National Park by the federal government for possession of marijuana. The marijuana was seized from his camping tent without a warrant. The officers removed a tarp from the top of the tent and found the marijuana inside. Your client is currently being charged with felony possession because this is his third offense, and he has chosen to plead the Fifth. Build a case for his defense using the equal protection clause of the Fourteenth Amendment and the exclusionary rule of the Fourth Amendment. Then explain if this defense would change significantly had he been arrested and charged by the Arizona state government and not the federal government. Some things to consider: Was the evidence obtained legally? Does federal policy supercede state law? Your client is facing three years in jail and a $5,000 fine. Is this punishment excessive? Can you find any recent cases that pertain, i.e., the development of jurisprudence in this area that may help build your case? Remember originally the Bill of Rights only applied to the federal government, and through the process of selective incorporation, most now apply to the states as well.

First, the key piece of material evidence in this case —the marijuana—must be excluded as it is "fruit of the poisonous tree." The fruit of the poisonous tree doctrine generally says that evidence obtained illegally is not admissible in court. In this case, the marijuana was discovered after the residence (the tent) of the defendant was searched without probable cause or a search warrant—the general requirements for police entry required by the fourth amendment.

Second, the equal protection clause of the 14th amendment establishes that all citizens of the United States should be treated equally under the law. While possession of marijuana may be a federal crime, it is legal in California and to prosecute a Californian within California for an act for which Californians in other parts of the state would not be subject to prosecution would be a violation of equal protection. However, were he arrested in Arizona, the equal protection argument might not apply, as no differential application would come into play, Arizona not having legalized marijuana in the first place.


The equal protection argument with respect to marijuana possession is currently being argued in the case of Washington, et. al v. Sessions.
Finally, the penalty of three years imprisonment and a $5,000 fine may or may not be excessive, however, the constitution only prohibits punishment which meets the two-part test of being (a) cruel, and, (b) unusual. In Furman v. Georgia the court set-out a high threshold of requirements for something to be both cruel and unusual, none of which are met by the penalty faced by the defendant in this hypothetical case.
http://www.hillerpc.com/wp-content/uploads/2017/07/Filed-Complaint-with-Dkt.-No.pdf

https://www.law.cornell.edu/wex/fruit_of_the_poisonous_tree

The Fourth Amendment of the US Constitution prohibits "unreasonable searches and seizures." Through the incorporation doctrine, the Fourth Amendment applies to the states as well as to the federal government (Mapp v. Ohio). Evidence found during an unreasonable search or seizure is excluded from court through the exclusionary rule.
Searches that are conducted without a warrant are unreasonable unless they fall into one of a small category of permissible exceptions. These are:
When police have to take immediate action to prevent evidence from being destroyed (the exigency exception).
Vehicle searches, which are permissible without a warrant because vehicles can be moved quickly, taking any evidence with them.
A search incident to an arrest, which allows police to search a suspect being apprehended, as well as his or her immediate surroundings.
A search done with a suspect's consent.
A search of areas that are within an officer's plain view, provided that the officer is legally standing in a public place.
The open fields exception, which allows police to search your land, provided you do not have a reasonable expectation of privacy in it.
Only the last two are closely applicable. The fact that the police needed to move a tarp to find the marijuana, though, eliminates these as a valid reason for the search. This makes the search unreasonable, in violation of the Fourth Amendment, and therefore illegal. It would be excluded from court and could not be used against the defendant.
The defense would not change significantly if the arrest had happened in Arizona by state law enforcement. The US Constitution provides civil rights that are considered the "floor": states can offer individual rights that surpass what the US Constitution offers, through their own state constitutions, but they can never offer less.
The three year, $5,000 fine punishment is far from excessive. In fact, it is relatively lenient for a third-time felony offense. Excessive punishment cases under the Eighth Amendment tend to involve extremely high sentences, and the bar is very high for the punishment to be excessive: A 25-years-to-life sentence under California's "three strikes law" in Ewing v. California for a defendant who stole three golf clubs was found to not be excessive.