During the early 1950s, the tactics of Senator Joseph McCarthy were criticized because he... a.) violated important constitutional liberties
b.) ignored evidence of Soviet spying
c.) opposed the use of loyalty oaths
d.) displayed racial prejudice in his questions

a.) violated important constitutional liberties.

Explanation:

Joseph Raymond McCarthy was an American public official, politician and lawyer born on the 14th, November 1908, Wisconsin, United States of America. He was considered to be an embarrassment to the Republican party by 1954.

Furthermore, Joseph asserted in a speech in the year 1950 that, he had a list of 205 communists and members of a spy ring who were working for the State Department at the time.

Additionally, he posited that there were infiltration by the members of the communist party into the US Army, President Harry Truman's cabinet and the Voice of America. For his accusations, Joseph was later censured by the Senate on the 2nd December of 1954, with a vote of 67–22 as a disciplinary action.

During the early 1950s, the tactics of Senator Joseph McCarthy were criticized because he violated important constitutional liberties.

In conclusion, false accusations against the U.S. Army led to the demise of Senator Joseph McCarthy at the age of 48, in Walter Reed National Military Medical Center, Bethesda on the 2nd of May, 1957.

c) legal battles last five weeks after the election due to the narrow victory in several states.