Sorry, but you are literally making the same argument that those who use the term "constitutional republic" are making- which is to string two words together: Constitutional + Republic- and assert that the combined words have a different or greater meaning than each word does separately!

Constitutional merely means we have a constitution- nothing more.

Republic - the definition of which means we have a government by elected representatives (versus direct democracy where EVERY citizen votes on every law)- nothing more.

There is NOTHING in either separate definitions or combining the two words to assert that we cannot or should not be an actual democracy.

Your statement "The 51% enslave the 49% and the minority has zero rights if the 51% don't allow it." is reflective of REVISIONISM. If you really want to know founders' intent, Madison, during the Constitutional Convention, clearly wanted simple majority rule both in the Congress and among the states when ratification took place. The Articles of Confederation specifically spelled out super-majorities for enactment of many laws and it was NOT working.

The framers of the constitution set about to have a majority vote process which has since been undermined. They protected the rights of (some) minorities within the Constitution and its amendments- nothing more. The reality is a minority have become a tyranny over the majority in this country!

The framers wanted a democratic vote for their representatives as well- except at the time, their democracy only included white men with property. This franchise was gradually expanded which made us move closer to a "more perfect union" but we now see a minority (Republicans) again move to suppress rights.