Lobbyists - along with interest groups - are common sources of legislation. Support for given candidates guarantees an entry point into the legislative process, but is this proper? Is it another example the undue influence of special interests? Maybe both.
The NYT reports on a bill which passed a House committee that was largely written by Citigroup.
Slate argues that this is to be expected when resources for legislators are limited.
Some academics call lobbying a type of legislative subsidy, meaning that they now perform an essential function for the legislature.