The United States Constitution is under constant attack and threat of being undermined and its expressed powers and rights being usurped. The Constitution requires the support of the American citizenry to allow it to continue to stand the test of time as a bulwark of liberty. Any action, whether through ignorance, inattention or ill intent, that effectively changes the meaning or effect of the Constitution without abiding the process provided for constitutional amendment, undermines the validity of the Constitution. When any part of the Constitution is undermined, or its powers and rights usurped, the remainder of the Constitution is diminished and the very rule of law in the United States becomes endangered.
There are several ways by which the Constitution is undermined and attacked:
Judicial Fiat - Courts have power to provide opinion on the constitutionality of laws, but they have no power to create law. Too often judicial opinion overreaches, and excerpts portions of laws changing the legal intent, or creates entirely new "law" from a contrived view of the law under review. Neither is constitutional, all federal laws are sourced by Congress in accordance with the Constitution.
Strangulation by Legislation - The Congress, perhaps the branch of government most entrusted to keep the Constitution, can become an opponent of the Constitution. The creation of numerous and incrementally more restrictive laws, particularly around rights specifically afforded, dulls and dilutes the value and protection of the Constitution.
Executive Orders - The President may issue orders, originally designed for the implementation of the executive function in running the government. Increasingly (although Franklin Roosevelt used more than any), Presidents are issuing orders that change the intent or implementation of existing laws or effectively create law, entirely bypassing Congress.
International Treaty - Under Article 6 of the Constitution, treaties are given equal status as supreme law of the land. As such, treaties having provisions counter to the Constitution have been used to challenge the validity of the very Constitution that gives them their authority.
Revisionism - Subtle and deceptive political groups may also advocate the usurpation of Constitutional rights. Articles and opinion pieces often advocate change, outside of Constitutional process, in the name of "progress." Watchwords of this tact of usurpation often include phrases such as "Modern times," "This day and age," "Old ways," and "Old thinking." For example, saying that "In these modern times there is no need for bearing arms because..." is a call for usurpation of Constitutional rights, unless advocating that change via the Constitutional process.
Reactionism - Emotional reaction, particularly following a natural or criminal tragedy is often leveraged as rationale for enactment of laws that support strangulation by legislation. While sympathy for those suffering from tragedy and a desire to protect against future tragedy is important to a society, such emotion may lead to swift reaction which is a poor protector of liberty. The structure of the American Republic and its Constitution provide for a process by which the sharp peaks and valleys of reactions are tempered.
All of these attacks on the Constitution must be defended by Americans who support the Constitution. Educate, express opinions in public, discuss issues with your neighbors, express beliefs to representatives, participate in government, protest and act with civil disobedience, and ultimately, when beyond "light and transient causes," exercise the Right of the People to "alter or to abolish ... and to institute new Government..."