The Second US Constitutional Amendment of guarantees right to bear arms and the Fifth US Constitutional Amendment requires the due process of law before depriving people of their rights.
According to the Fifth US Constitutional Amendment, No person shall be held to answer for a capital, or otherwise infamous crime, unless on a presentment or indictment of a grand jury, except in cases arising in the land or naval forces, or in the militia, when in actual service in time of war or public danger; nor shall any person be subject for the same offense to be twice put in jeopardy of life or limb; nor shall be compelled in any criminal case to be a witness against himself, nor be deprived of life, liberty, or property, without due process of law; nor shall private property be taken for public use, without just compensation.
The very existence of secret lists (no-fly list) is abhorrent in a free society. If the government can’t make a case against you in open court, the government needs knock it off. If the government can only maintain power with the aid of such lists, it’s a government that does not deserve to exist.
No-fly list serve no honest purpose in a free society. No punishment means you can’t exclude someone from exercising a specifically-enumerated civil rights guaranteed by the constitution, because the words innocent until proven guilty although not in the Constitution are the foundation of the entire US justice system.
Hence, the No-fly list that result in denial of rights without any notice, arrest, trial, or conviction can only be viewed, legally speaking, as the exact kind of monarchial practice the Founders sought to squash—not limit—from the outset.
Thus, banning guns for those people who are in the secret list is obviously a violation of due process of law.