Attorney general a. mitchell palmer believed that he needed to protect the american people from

Political radical

Explanation:

Alexander Mitchell Palmer served as an Attorney General of the United States from 1919-1921 after World War 1.

The most remembered service of Palmer is the "Palmer Raids." The Palmer Raids was the series of arrests and roundups of suspected leftists in 1919-1920. Mitchell in his speech expressed his suspicion on the leftists for the bombings happening in the States. He said that he fears that communists are eating up the homes of Americans with the bombings.

So, the correct answer is political radicals also known as communists.

the declaration states, “we hold these truths to be self-evident, that all men are created equal, that they are endowed by their creator with certain unalienable rights, that among these are life, liberty, and the pursuit of happiness….”