The constitutionality of each of the charges is well supported and there is no really viable First Amendment defense to any of them.
There is literally a U.S. Justice Department handbook on how to prosecute attempts to undermine the integrity of elections accumulating the wisdom its has gleaned from doing precisely what it is doing in this indictment, successfully, for generations.
18 U.S.C. § 371 (Conspiracy to Defraud the United States)
This statute states that:
If two or more persons conspire either to commit any offense against
the United States, or to defraud the United States, or any agency
thereof in any manner or for any purpose, and one or more of such
persons do any act to effect the object of the conspiracy, each shall
be fined under this title or imprisoned not more than five years, or
If, however, the offense, the commission of which is the object of the
conspiracy, is a misdemeanor only, the punishment for such conspiracy
shall not exceed the maximum punishment provided for such misdemeanor.
Fraudulent statements which are protected by the First Amendment are the exception more than they are the rule. When fraudulent statements of presenting existing facts, or fraudulent concealment of presently existing facts, seek to impair someone's legal rights, it is generally constitutional to punish that conduct criminally.
At noted here:
Fraud and Perjury
While, again, the First Amendment makes no categorical exception for
false or misleading speech, certain types of fraudulent statements
fall outside its protection. The government generally can impose
liability for false advertising or on speakers who knowingly make
factual misrepresentations to obtain money or some other material
benefit (such as employment). Prohibitions on perjury — knowingly
giving false testimony under oath — also are constitutional.
This statute requires proof of intentional fraud, and not just a good faith difference of opinion sincerely held by the defendant.
Probably the most on point precedent upholding the constitutionality of this statute in an analogous context is United States v. Rafoi, 60 F.4th 982 (5th Cir. 2023).
This case held that the statute was constitutional where the charged conduct caused harm inside United States or to United States citizens or interests, that provided sufficient nexus, as required by due process, between United States and defendant's conduct in allegedly meeting with co-conspirators in Miami, Florida, where a noncitizen defendant, a citizen of Portugal and Switzerland who was employee of Swiss wealth-management firm, conspired to violate Foreign Corrupt Practices Act (FCPA) as agent of a person while in United States, relating to alleged international bribery scheme between businesses based in United States and Venezuelan officials and the defendant has the intent or knowledge that the monies involved were proceeds of specified unlawful activity would be unlawfully transmitted from or through a place in United States to a place outside United States.
The relevant holding in this case is that prosecuting violations of U.S. laws that exist for the purposes of insisting upon orderly and non-corrupt conduct of actions related to U.S. officials or U.S. persons through fraud under this statute, is constitutional. When it affects the conduct of U.S. government business, or of a U.S. business or person, the statute is actionable and constitutional.
Also pertinent is a much older U.S. Supreme Court decision, Hammerschmidt v. United States, 265 U.S. 182 (1924):
[F]ormer President and Chief Justice of the Supreme Court William
Howard Taft explained in a landmark 1924 opinion, the full meaning of
the statute almost anticipates our current surreal scenario: “It also
means to interfere with or obstruct one of its [the country’s] lawful
governmental functions by deceit, craft or trickery, or at least by
means that are dishonest."
In contrast, fraud in the course of a political campaign to persuade voters is protected by the First Amendment. See United States v. Alvarez, 567 U.S. 709 (2012) (holding that a law criminalizing false factual statements about military honors received in a political campaign called the "Stolen Valor Act" in the version then in force was unconstitutional on First Amendment grounds). But that isn't what this charged is seeking to prosecute. A law review article from 2015 attempts to clarify the scope of Alvarez, distinguishing between completely unprotected lies, lies that are protected so as not to chill the expression of truthful statements, and "lies that must be protected for their own sake". The citation to the article is Alan K. Chen and Justin Marceau, "High Value Lies, Ugly Truths, and the First Amendment," 68 Vanderbilt Law Review 1435 (2015).
It is notable that in Alvarez every conservative justice on the Court at the time other than Chief Justice Roberts, voted to affirm the constitutionality of the "Stolen Valor Act", over a mostly liberal majority that held that it was an unconstitutional violation of free speech rights. Now that there is a six justice conservative majority in the U.S. Supreme Court, if the positions of conservative justices on the issue was consistent, the U.S. Supreme Court would be even more likely to uphold the constitutionality of a prosecution under 18 U.S.C. § 371 than the U.S. Supreme Court would have been inclined to in 2012.
It is unclear, however, how much this conservative ruling was dependent upon the fact that the statute prohibited lying about military honors rather than about other matters. Conservatives tend to hold honor, and in particular, military honors, in greater esteem than liberals. Also, conservative justice may have been more clear than the liberal justices in that case about just how open and shut these cases were, since the truth or falsity of the statement can be determined definitively, from a single official document, the veteran's Form DD214, which there is a strong presumption that almost any veteran capable of running for political office would understand perfectly well.
Another issue which influenced swing votes in the Alvarez case is that the statute that the U.S. Supreme Court considered at the time criminalized fraud regarding military honors even when it was arguably immaterial (e.g. in dinner table conservations with friends or family, as opposed to only in the context of an election campaign, or only in a request for economic benefits or legal privileges). This concern is not present in this particular prosecution under 18 U.S.C. § 371, since Donald Trump would receive the legal benefit of being re-elected as President of the United States if his alleged election results related fraud conspiracy was successful.
One critical distinction, previously noted by the Washington State Supreme Court its 2007 decision in the case of Rickert v Washington, is whether, in the context of the speech giving rise to the legal consequences, "the government is capable of correctly and consistently negotiating the thin line between fact and opinion in political speech." This will generally be true in the case of factual statements related to election results and administration, but will generally not be true in wide ranging statements about policy issues in the course of a political campaign.
An August 1, 2022 report of the Congressional Research Service, the non-partisan research arm of Congress, generally confirms the analysis above.
This is the only D.C. grand jury indictment for which there is even a colorable free speech argument, but given the case law, it is a weak argument.
18 U.S.C. §§ 1512 (Obstruction of and Attempt to Obstruct an Official Proceeding and Conspiracy To Do The Same)
Obstruction of an official proceeding in action action with an intended effect and doesn't prevent people from expressing opinions in a way that does not obstruct official government functions, so again this isn't unconstitutional. The charge in this case charges the crime that:
Whoever corruptly-- obstructs, influences, or impedes any official
proceeding, or attempts to do so
is guilty of a felony punishable by up to twenty years in prison.
There is already case law testing the constitutionality of this portion of this statute in the context of the same course of conduct related to the January 6, 2021 riot by a lower level minor from the D.C. Circuit whose rulings are binding precedents in this indictment. United States v. Fischer, 64 F.4th 329 (D.C. Cir. 2023).
The foundation for this ruling is longstanding:
Speech Integral to Criminal Conduct
In Giboney v. Empire Storage & Ice Co. (1949), the Supreme Court
held the First Amendment affords no protection to “speech or writing
used as an integral part of conduct in violation of a valid criminal
statute.” A robber’s demand at gunpoint that you hand over your money
is not protected speech. Nor is extortion, criminal conspiracy, or
solicitation to commit a specific crime. Abstract advocacy of
lawbreaking remains protected speech.
There is no constitutional basis to distinguish a direct charge of obstruction with official business from a conspiracy charge to do the same.
In the case of the conspiracy to obstruct charge, the co-conspirators take actions that collectively seek to deprive people of their constitutional rights or obstruct an official proceeding, the statements made in furtherance of the group effort to achieve those ends are not legally protected speech. It is the action (either a verbal act or another kind of act) and not the expressive content of the speech that is implicated.
18 U.S.C. § 241 (Conspiracy Against Rights)
A conspiracy to cause false election results to be certified to Congress to change the results of a Presidential election by two or more persons impairs the constitutional right to vote, and rights under Congressional adopted federal election laws.
Notably, a conspiracy to violate rights, which is a felony punishable by up to death if the conspiracy causes someone's death (as can be plausibly alleged in this case due to a death arising from the January 6, 2021 riot) provides that the felony has been committed:
If two or more persons conspire to injure, oppress, threaten, or
intimidate any person in any State, Territory, Commonwealth,
Possession, or District in the free exercise or enjoyment of any right
or privilege secured to him by the Constitution or laws of the United
States, or because of his having so exercised the same.
The U.S. Supreme Court has previously held that prosecuting conspirators for tampering with the process of determining the correct result of the election is constitutional. U.S. v. Saylor, 322 U.S. 385 (1944).
This also comes within the "Speech Integral to Criminal Conduct" exception to the protections of the First Amendment that is discussed above.
FOOTNOTE: If the Justice Department sought the death penalty on this criminal charge the jury would have to be "death qualified" in the court of jury selection which tends to make the jury more conservative. But, there is no indication that the Justice Department intends to seek this relief in this particular prosecution of Donald Trump.
As a practical matter, given Donald Trump's age, health, and the length of time necessary to fully appeal a death penalty conviction (which exceeds ten years in most cases), any criminal conviction with a sentences of ten or fifteen years or more would as a practical matter result in him dying in prison, and it is unlikely that appeals of a death sentence would be completed before he died of natural causes.