In the latest Critical Review, Jeffrey Friedman argues against those who would interpret politics entirely in terms of individual interests. He says that ideas matter, and that ideas do not necessarily coincide with interests. However, things like the squelching of patent reform are indicative that interest matter.
The Murray Edelman view of politics that I learned at my father’s knee was one in which ideas do not matter. Instead, politics is a contest among insiders (as in the linked story, between tech lobbyists and trial-lawyer lobbyists), who have rational interests. The public is treated to political theater, using what Edelman called symbols. While the public is paying attention to the theatrics (think of Ferguson, or ISIS, or the controversies over contraception and Obamacare), the insiders are helping themselves to the real goodies.
I think by ideas you mean ideals. Some people are idealist. Prof Murray Edelman’s daughter for example is here organizing nice bar-mitzvah to poor children.
Wouldn’t it be interesting to ask a congressman: If there were two possible districts to put a big job generating project, your district or the poorest district in the country, like in Mississippi or eastern Kentucky, all else being equal where would you vote to put it?