From a reader:

Of all the areas of modern legislative activity, isn’t earmarking just about the least prone to lobbying? How much persuading from special interests does a Congressman really need to spend money in his own district and employ his own constituents on federal projects?
If you are a Congressman from (say) Kansas, here’s how you are likely to feel about three sample issues:
1. Regulation of ocean-going container ships [Gee, I dunno. There’s no seaports in Kansas. Wonder what the trade associations have to say. I’ll probably hear from shipowners, and terminal operators, and maybe the longshoreman’s union. And then there are the manufacturers who import parts or export finished products.]
2. Corn and wheat subsidies [Well, I’m in favor, of course, but I’ll have to look at the bill carefully to make sure that Iowa or Nebraska don’t get more out of it than Kansas does].
3. Building a highway in your district [Tell K Street not to bother calling. Just show me where I sign.]