Federal policy, at the highest level, is made by elected representatives (the president and members of Congress). The opinion of the American people matters because their understanding and views about S&T can influence their vote. While various opinion polls (e.g. The Science and Engineering Indicators, published by the NSF) show that the majority of Americans have a positive attitude toward S&T. People are interested in hearing about scientific discoveries, appreciate the benefits to their lives, and are happy to see their tax dollars spent on research, but it is not clear that a politician's views on S&T are at all an issue at election time.
The public's perception of science is heavily influenced by the media. While scientists often complain about how science is covered, there is no shortage of news about the latest discoveries in astronomy, physics, biology, medicine and many other areas.
Examples:
Science Friday, Kids' Connection, and the Listener's Lounge (a forum where callers voice their reactions and ask questions) are all aired on the National Public Radio.
TV has science shows including Bill Nye the Science Guy, who explains complex scientific concepts for a young audience, and the many programs aired on the Discovery Channel.
The web also has plenty of science to offer. One example is the Yahoo site Yahooligans, which has links to astronomy, animals, careers, museums and centers, engineering, weather, computer science, and many other scientific and technical topics.