Complex sentence: O'Daniel refused to run for another term in 1948, but ran for governor of Texas in 1956 and 1958 and claimed that the Brown v. Board of Education decision was part of a communist conspiracy.
Split into simpler sentences: O'Daniel refused to run for another term in 1948. He ran for governor of Texas in 1956 and 1958 and claimed that the Brown v. Board of Education decision was part of a communist conspiracy.