Their motive for doing so is apparently to suggest that the passage involved is “proof” that the illustrious long-departed would most certainly approve of the speaker. 

Now clearly, in the absence of an ability to communicate with the dead, such a claim cannot be validated. Or invalidated, for that matter. 

However, you can tell a great deal about someone else's philosophy of life through his or her writings. Enough to allow you to decide for yourself whether or not the Founding Father quoted would, indeed, approve of the Oval Office occupant making the claim. 

With that in mind, let me offer you Thomas Jefferson's 10 rules for life. 

Never put off until tomorrow what you can do today. 
Never trouble another person to do for you what you can do for yourself. 

Never spend money before you've earned it. 

Never buy what you don't want just because it's cheap. 

Beware of pride. It will cost you far more than hunger, thirst, and cold. 

Remember that we seldom regret having eaten too little. 

Remember that nothing is troublesome that we do willingly. 

Remember that worry will cause much pain over things that will never happen. 

Take things always by the smooth handle. 

When angry, count to ten before you speak. When very angry, count to 100.

Think about it.