"Moderate" often means apathetic: Moderates are often portrayed as responsible people, while strong conservatives or liberals are described as "extremists." In my experience, it is more accurate to divide people into two groups of "give a damn" and "don't give a damn." The GSS backs me up here. Respondents were asked how important politics and public life were to them, and answers ranged from 1 (unimportant) to 7 (very important). I calculated the average score for these groups:

Importance of politics
1. Extremely liberal 4.47
2. Conservative 4.34
3. Liberal 4.30
4. Extremely conservative 4.25
5. Slightly liberal 4.07
6. Slightly conservative 4.03
7. Moderate 4.03

Not only is politics relatively unimportant to moderates, they are less informed. Here is the percent who know who their U.S. Representative is:

Percent who know who U.S. Representative is:
1. Extremely conservative 91.7
2. Extremely liberal 88.9
3. Liberal 85.1
4. Slightly liberal 82.5
5. Conservative 80.9
6. Slightly conservative 80.3
7. Moderate 75.3