Politics and new media structure
At a fundamental level, way below the level of politics, the Internet (or new media) is bi-directional. Older political technologies (e.g., television, radio, newspapers, pamphlets, etc.) are uni-directional. Howard notes that before 1960, American political consultants gauged public opinion at union meetings, town halls, etc.; between 1960 and the late 1980s, consultants used focus groups to sample citizens' opinions. Now the Internet allows (at least at its most basic level) continual production by its users. I would argue (as would many other people--nothing original here) that this has led to transformations in marketing, sales, entertainment and slew of other fields, not only politics. Moreover, I think a better title for Howard's book would have been Data-driven Campaigns and the Managed Citizen. In my opinion, it is the data gathered from the surveillance of Internet use that most directly transforms political campaigns. (An interesting side note: this is a fundamental Internet design decision. Take a look at EFF's Tor. Could you design something similar for credit card purchases?)
While my opinion diverges from Howard, I should point out that he believes that new media fundamentally allows campaign managers to target individually-tailored political messages. Further, he concludes that new media helps degrade the public sphere by creating a personal information tunnel between a citizen and a campaign. In Howard's view, new media serves to create an echo chamber where you are rarely, if ever, exposed to challenging ideas.