Answer:
It ensured that state governments had to respect most Bill of
Rights protections.
Explanation:
Selective incorporation is a term that describes the process in which the US supreme Court decides that the Bill of Rights established in the Constitution are not infringed by the states.
In other words, it is a process where by the Supreme Court ensures state governmen follow the established or certian limitation formerly only placed on the federal government when it comes to Bill of Rights.
Hence, the process of selective incorporation influence the U.S. government in the 20th century as "It ensured that state governments had to respect most Bill of Rights protections."