This is an important point from Nancy Scola that both veteran observers of the legislative process and political scientists deem important, but that ordinary people and many journalists tend to neglect:
An alternative theory of Congress: They’re not crooks, they’re idiots! So many members of Congress — too many of them — outsource their thinking, and voting, on all but the matters most central to their own affairs, to the think tanks and lobbyists who are paid, well, to produce articulate and generally verifiable (though, naturally, quite biased) talking points, background memoranda, and opening statements on whichever topics matter most to their interests. I think Lessig’s approach, in the early going, has flaws too. But the weak spot seems to be in not devoting enough attention to how information flows through Congress — not in its failure to paint legislatures evilly enough.
This is roughly speaking the theory of lobbying as “legislative subsidy”. A member of congress only has so much money to spend on staff. And the demands on his or her time are enormous. When a constituent asks about something, you can’t say “look, to be honest I spend all my substantive time on parochial BS or else topics that my subcommittee has jurisdiction over.” So members have a lot of reason to lean heavily on a set of interest-group advocates who they’ve decided are the ones they want to affiliate with. Meanwhile interest groups have a clear incentive of providing financial backing for the members of congress who rely on them, a dynamic that’s often glossed as the recipient of the funds being on the take, which likely misstates the real causal links.