What motivated the Founding Fathers to include the phrase "we the People" in the Preamble of U.S. Constitution?
We the people was a statement that the power of government comes from the people not the elite or political class or nobility .
The Government in England was based on the King. The House of Lords the most powerful part of the Parliament was based on nobility. Only the house of Commons gave power to the people.
The American Experiment in government was to give power to the people. The elite no longer had complete control over the rest of the population. Starting with the phrase We the people was to make this clear.