There are several treason and sedition crimes in federal law all of which are defined by statute.
Treason Offenses
Treason offenses pertain to acts in furtherance of a foreign country or sometimes more specifically a foreign country with which the United States is at war (which is the legal definition of an "enemy"). These include Sections 2381, 2382, some of the subsections of 2386, 2388, 2389 and 2390.
They are:
18 USC § 2381. Treason ("Whoever, owing allegiance to the United States, levies war against them or adheres to their enemies, giving them aid and comfort within the United States or elsewhere, is guilty of treason and shall suffer death, or shall be imprisoned not less than five years and fined under this title but not less than $10,000; and shall be incapable of holding any office under the United States.")
18 USC § 2382. Misprision of treason (i.e. failure to report knowledge of someone else's treason to an appropriate government official).
18 USC § 2386. Registration of certain organizations (the guts of this offense's treason component are found in part B(1) which provides that: "The following organizations shall be required to register with the Attorney General: Every organization subject to foreign control which engages in political activity; . . . [and] Every organization subject to foreign control which engages in civilian military activity")
18 USC § 2388. Activities affecting armed forces during war
18 USC § 2389. Recruiting for service against United States
18 USC § 2390. Enlistment to serve against United States
None of these are implicated by the question.
Sedition Offenses
Sedition offenses pertain to acts to overthrow or interfere with the government that do not have a clear nexus with a foreign country.These include Sections 2383, 2384, 2385, some of the subsections of 2386, and 2387. They are:
18 USC § 2383. Rebellion or insurrection (see below)
18 USC § 2384. Seditious conspiracy (see below)
18 USC § 2385. Advocating overthrow of Government
Whoever knowingly or willfully advocates, abets, advises, or teaches
the duty, necessity, desirability, or propriety of overthrowing or
destroying the government of the United States or the government of
any State, Territory, District or Possession thereof, or the
government of any political subdivision therein, by force or violence,
or by the assassination of any officer of any such government; or
Whoever, with intent to cause the overthrow or destruction of any such
government, prints, publishes, edits, issues, circulates, sells,
distributes, or publicly displays any written or printed matter
advocating, advising, or teaching the duty, necessity, desirability,
or propriety of overthrowing or destroying any government in the
United States by force or violence, or attempts to do so; or
Whoever organizes or helps or attempts to organize any society, group,
or assembly of persons who teach, advocate, or encourage the overthrow
or destruction of any such government by force or violence; or
becomes or is a member of, or affiliates with, any such society,
group, or assembly of persons, knowing the purposes thereof--
Shall be fined under this title or imprisoned not more than twenty
years, or both, and shall be ineligible for employment by the United
States or any department or agency thereof, for the five years next
following his conviction.
If two or more persons conspire to commit any offense named in this
section, each shall be fined under this title or imprisoned not more
than twenty years, or both, and shall be ineligible for employment by
the United States or any department or agency thereof, for the five
years next following his conviction.
As used in this section, the terms “organizes” and “organize”, with
respect to any society, group, or assembly of persons, include the
recruiting of new members, the forming of new units, and the
regrouping or expansion of existing clubs, classes, and other units of
such society, group, or assembly of persons.
18 USC § 2386. Registration of certain organizations (the guts of this offense are found in part B(1) which provides that: "The following organizations shall be required to register with the Attorney General: . . . . Every organization which engages both in civilian military activity and in political activity; . . . and Every organization, the purpose or aim of which, or one of the purposes or aims of which, is the establishment, control, conduct, seizure, or overthrow of a government or subdivision thereof by the use of force, violence, military measures, or threats of any one or more of the foregoing.")
18 USC § 2387. Activities affecting armed forces generally (in the pertinent part: "Whoever, with intent to interfere with, impair, or influence the loyalty, morale, or discipline of the military or naval forces of the United States: (1) advises, counsels, urges, or in any manner causes or attempts to cause insubordination, disloyalty, mutiny, or refusal of duty by any member of the military or naval forces of the United States; or (2) distributes or attempts to distribute any written or printed matter which advises, counsels, or urges insubordination, disloyalty, mutiny, or refusal of duty by any member of the military or naval forces of the United States-- Shall be fined under this title or imprisoned not more than ten years, or both, and shall be ineligible for employment by the United States or any department or agency thereof, for the five years next following his conviction.")
But the sedition offenses potentially pertinent to the question are Sections 2383 and 2384. They are as follows (emphasis added)
18 USC § 2383. Rebellion or insurrection
Whoever incites, sets on foot, assists, or engages in any rebellion or
insurrection against the authority of the United States or the laws
thereof, or gives aid or comfort thereto, shall be fined under this
title or imprisoned not more than ten years, or both; and shall be
incapable of holding any office under the United States.
And also (line breaks and line numbers inserted editorially for ease of reading and discussion purposes):
18 USC §2384—Seditious Conspiracy
(1) If two or more persons
(2) in any State or Territory, or in any place subject to the jurisdiction
of the United States,
(3) conspire
(4) to overthrow, put down, or to destroy by force the Government of the
United States, or to levy war against them,
(5) or to oppose by force the authority thereof,
(6) or by force to prevent, hinder, or delay the execution of any law of
the United States,
(7) or by force to seize, take, or possess any property of the United
States contrary to the authority thereof,
(8) they shall each be fined under this title or imprisoned not more than
twenty years, or both.
Lines (1), (2) and (3) are elements of the offense which must be established beyond a reasonable doubt by the prosecution in a criminal trial. In addition one of the four elements (4), (5), (6) or (7) must be established beyond a reasonable doubt by the prosecution in a criminal trial. Elements (6) and (7) are particularly relevant to the question here.
The meaning of the words used in those elements is further defined in case law interpreting the statute in connection with the preparation of a jury instruction applying this statute to the facts presented at trial in a case (as well as lots of more general instructions on how a jury makes factual determinations). Only elements of the offense upon which some evidence has been presented by the prosecution are included in jury instructions.
But the definitions in a jury instruction which is operationally the law in any particular case doesn't get a whole lot more specific than the statutory language quoted above. Ultimately, any vagueness in that language has to be resolved unanimously by the jury (or by a judge in a trial to the court).
If these elements are established, the maximum punishment of (8) is authorized.
Caveat
The discretion of the sentencing judge to impose a sentence is not nearly as unfettered as it appears due to general provisions of Title 18 of the United States Code related to the exercise of sentencing discretion by a judge which incorporate by reference the federal sentencing guidelines adopted by an appointed federal government commission. These guidelines are advisory, rather than mandatory, but still have real effect. A judge has to calculated the guideline sentence, then articulate based upon judicial findings of fact any reason for deviating from the guideline sentencing range, and if this process is not followed, or if the findings of fact made aren't supported by the trial court record or don't support the conclusion reached, the sentence can be reversed for an abuse of discretion when the guideline sentence isn't followed, even if the maximum sentence authorized by this statute is not exceeded.