This makes them answer to moneyed interests, not to voters. The only thing that is going to fix this is some serious campaign and lobbying reform. It's not very popular to say but we need to provide some form of public campaign financing. If you ask one of these large campaign contributors if they are buying votes, they will tell you, quite sincerely, that they are merely buying access. Let's be honest.
Access means influence.
Along with public funding, we have to put serious limits on how much any one person can donate to a campaign. This would prevent any one person from buying large amounts of influence. Also, only individuals should be allowed to make campaign contributions. Our constitution doesn't give corporations, PACs, or any other organization the right to vote. This right is reserved for the individual.