Part 2 to Question: are you in the wrong country?

Defend the Constitution against all enemies, foreign and domestic" is a solemn oath taken by U.S. officials (civil, military, and naturalized citizens) pledging loyalty to the Constitution....

"I do solemnly swear (or affirm) that I will support and defend the Constitution of the United States against all enemies, foreign and domestic; that I will bear true faith and allegiance to the same; that I take this obligation freely, without any mental reservation or purpose of evasion; and that I will well and faithfully discharge the duties of the office on which I am about to enter" is the core pledge for U.S. officials, military, and new citizens, affirming loyalty not to individuals but to the Constitution as the supreme law, a commitment binding them to uphold its principles against threats from any source, ensuring accountability to the nation's founding document. 

Who Takes This Oath?

• U.S. Officials: Presidents, Members of Congress, judges, and other federal officers swear to support the Constitution as outlined in Article VI.
• U.S. Military Personnel: Soldiers, sailors, airmen, and marines pledge allegiance to the Constitution, not a person, as stated by leaders like General Mark Milley.
• Naturalized Citizens: Immigrants becoming U.S. citizens take a similar Oath of Allegiance, renouncing foreign loyalties and promising to defend the Constitution. 
Key Components of the Oath
• "Support and defend the Constitution": A commitment to uphold the foundational laws and principles of the U.S..
• "Against all enemies, foreign and domestic": Acknowledges threats can come from outside or inside the country.
• "Bear true faith and allegiance": A pledge of loyalty to the Constitution itself.
• "Without mental reservation or purpose of evasion": A promise to uphold the oath honestly and fully. 
Significance
• Establishes Accountability: Ensures officials serve the Constitution, not personal interests or political factions, as seen in historic contexts like the post-Civil War era.
• Unifies Military: Underpins the unique American principle that the military serves the Constitution and the "idea that is America," not a leader.
• Foundation of Citizenship: Marks the final step for immigrants, solidifying their commitment to the nation's legal framework. 

Source: AI Overview, Google

Reference:

https://www.boundless.com/immigration-resources/us-citizenship-oath-of-allegiance-ceremony#:~:text=along%20the%20way.-,Full%20Text%20of%20the%20Oath%20of%20Allegiance%20to%20the%20United,the%20Oath%20of%20Allegiance%20ceremony.