Such limits invariably threaten free speech. The early campaign-finance legislation mentioned above would have limited candidates' spending on broadcast advertising, effectively suppressing some political speech. Restrictions on the political spending of corporations and labor unions, meanwhile, were a prior restraint on speech, a particularly severe form of censorship.
Such restrictions have been justified as preventing corruption, as campaign donors might buy official favors. Of course, bribery is already illegal, so corruption is redefined as "undue influence." The trouble is that those who stand to lose or gain much from public policy have every incentive to fight for their interests through political spending. If they succeed, have they had undue influence? Or is that just another way of saying the wrong side won?
Moreover, there is little evidence that money has much influence on policymakers. Political scientists have found that contributions explain little about lawmaking once ideology, party, and constituency are accounted for. One scholarly study of lobbying concluded that "the direct correlation between money and outcomes that so many political scientists have sought simply is not there."
Reformers also seek equality: If each voter has one vote, why should some be allowed to speak more loudly than others? But the Supreme Court has ruled that campaign-finance restrictions can't be justified on the basis of equality of voice. Making voices equal requires shutting up voices that are speaking "too much." We face a stark choice between equality and freedom of speech, and the Constitution rightly favors the latter.
