The question is about the United States but about it's legislativeprocess. As with every legislature, the representatives are made up of people. When the majority of the people in the house of representatives tilt in one direction, it becomes the decision of the whole. this is why it appears as though the US endorsed or institutionalized racism.
<h3>Why was Institutionalized racism allowed to happen?</h3>
One of the laws in the History of US that speaks to the above is Jim Crows law. This law favored racial segregation and empowered law enforcement agencies to enforce it.
The reason it was put in place is already indicated in the first paragraph. It is to be noted however that the Civil Rights Act of 1964 and The Voting Rights Act of 1965 overturned Jim Crows laws.
The Tenth Amendment of The United States Constitution is part of the Bill of Rights, which basically says that there was power not to be given to the federal government by the people or the state.
Tenth Amendment Put the Bill of Rights into the Constitution of the United States of America on September 5, 1789 and voted 9 of the 12 states December 15, 1791
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The Tenth Amendment helps define the concept of federalism, the relationship between federal and state governments.