McCain's signature issue is campaign finance reform, though he has watered down the legislation he has introduced to Congress on the subject.
He proposes banning soft money contributions from individuals, which he has said exert a corrupt influence on the political process. McCain supports so-called "paycheck protection," which could require unions and corporations to obtain their employees' consent before using company money for political purposes.
Opponents of McCain's legislation have said it is frought with logical problems. They have said McCain proposes a ban on individual giving to political campaigns on the grounds that politicians (including himself) cannot be trusted to ward off the influence the money is purported to buy. This penalizes the wrong agent, they believe. If politicians are to blame, why punish the citizens? If politicians play favorites their contributors, citizens will vote them out of office on election day.
McCain responds that political donations provide incentives for good politicians to go bad--and creates the appearance of conflicts where none exist.