How are the details presented about the various European political ideologies and regimes the American-born writers supported important in supporting the main idea of the passage

European ideologies have always held sway in US that gave it its distinctive brand in the nation.

Explanation:

European thinkers have always influenced the policy decisions in US to the capacity that their thoughts were brought to US, read and then worked upon by the natives in their own accord and in their own way.

This way, the ideas of liberty and fraternity were practiced in US constitution before it ever was in Europe.

This has to do with the fact that the concepts were headed by the the thinkers like Locke and Rousseau but ultimately it was the US that showed the world the real application of those ideas.