Final answer:
The quote that best supports the decision in Citizens United v. Federal Election Commission (2010) is from the Federalist Papers and emphasizes that attempting to limit or control factions would violate individual freedoms.
Step-by-step explanation:
The best quote from the Federalist Papers that supports the decision in Citizens United v. Federal Election Commission (2010) is:
"From this view of the subject, it may be concluded, that a pure Democracy, by which I mean a Society consisting of a small number of citizens, who assemble and administer the Government in person, can admit of no cure for the mischiefs of faction."
This quote highlights the understanding that factions, or special interest groups, are inevitable in a democratic society. It suggests that attempting to limit or control factions would violate individual freedoms. Instead, allowing factions to compete against each other is a natural way of controlling their influence.