Why did the Citizens United majority distinguish political access from corruption?

In the case of Citizens United v. Federal Election Commission, the Supreme Court majority distinguished political access from corruption to clarify the limits of government regulation under the First Amendment.1

The Court reasoned that while the government has a compelling interest in preventing corruption or the appearance of it, this interest is specifically tied to the prevention of quid pro quo arrangements—situations where political favors are directly exchanged for money. Because the independent expenditures at issue were, by definition, not coordinated or prearranged with a candidate or campaign, the Court concluded they could not result in such a direct exchange.1

Consequently, the majority held that while independent spending might lead to "ingratiation and access," allowing a corporation to gain a better opportunity to express its views to a candidate, this does not constitute corruption. By drawing this distinction, the Court determined that the government could not justify banning independent corporate expenditures on the grounds of preventing corruption, as such access is a common and protected aspect of the political process.1