Final answer:
The Supreme Court in Buckley v. Valeo ruled that spending money on political campaigns is a form of protected free speech under the First Amendment, and thus candidates cannot be overly restricted in how much they expend on their own campaigns.
Step-by-step explanation:
In the landmark Buckley v. Valeo decision of 1976, the Supreme Court established a pivotal principle regarding the financing of political campaigns. The Court held that spending money to influence elections is a form of constitutionally protected free speech. Thus, while the government was permitted to impose certain limits on campaign contributions, it could not generally restrict a candidate's ability to expend funds on their political campaign. Such restrictions were seen as a violation of the First Amendment rights related to freedom of speech, a cornerstone of political expression.