I'm posting this as Community Wiki so others can add to this.

## Traditional Measures ##

 1. The number of people in the organization, both as measured in dues
    paying members or volunteers, and employees.  This measure should be fairly self-evident; if a movement exists rather than an astroturf organization, it will be most conspicuous in the number of people it can mobilize.  Related is the ability to get out the vote or motivate to action third-party actors that are only [softly related to the movement or organization](https://listosaur.com/politics/10-powerful-special-interest-groups-america/).
 2. The amount of resources, especially money, the organization can lay claim to and bring to bear on campaigns and messaging.
 3. The number of "wins" at the policy level the organization has achieved, such as championing legislation, regulations, pro se or other litigation and other actions that have tangible results on the law.
 4. The ability to viewed as an expert (cited in the press, appears on talkshows, webpage visits.) [as the result of policy papers, experience, and/or research](https://thebestschools.org/features/most-influential-think-tanks/).
 5. The ability to change the culture through influence, communications, social media, events and symbols.  Tangentially related to the ability to move the [Overton Window](https://en.wikipedia.org/wiki/Overton_window). 
 6. The ability to keep things from being talked about, reported in the news, and/or otherwise scrutinized.