Citizens United won its case against the FEC primarily based on the First Amendment's Freedom of Speech. The Supreme Court ruled that restrictions on independent political expenditures by corporations and unions violated this right. Therefore, the correct answer is D. Freedom of Speech.
;
Citizens United won its Supreme Court case primarily on the basis of the First Amendment's Freedom of Speech . The ruling allowed for corporations and unions to spend unlimited amounts on political communications. Thus, the best answer is D. Freedom of Speech. ;