We didn’t have one our first hundred years. It was started by a socialist. It has a collectivist air about it. They used to say it while doing a nazi salute until that had to end in 1942. I read that changed to the hand on heart thing in 42. Pappy Boyington was in China with the Flying Tigers AVG when that change happened. He was at a ballgame and didn’t put his hand over his heart. Some locals wanted to fight him!
The Founders didn’t need one...maybe we don’t.
Allegiance = fealty
fe·al·ty
nounHISTORICAL
a feudal tenant's or vassal's sworn loyalty to a lord.
"they owed fealty to the Earl rather than the King"
formal acknowledgment of loyalty to a lord.
"a property for which she did fealty"
The pledge is an Oath that makes us subjects, not citizens, and is contrary to the very concept of a Republic.
The Founders wouldn't have been caught dead saying it.