The 1st Amendment protects the right to speak, not the right to spend.
Source: Dissenting opinion in 7-2 ruling that struck down $1,000 legal limit on spending by political action committees on behalf of presidential candidates, 18 Mar 85
-- Byron R White, (Jun 8 1917-2002), US jurist; He was an associate justice of the U.S. Supreme Court, 1962-93; he also played professional football for one season (1938) with the Pittsburgh Pirates (now Steelers).