These are “operational entities formed by critical infrastructure owners and operators to gather, analyze, appropriately sanitize, and disseminate intelligence and information related to critical infrastructure. ISACs provide 24/7 threat warning and incident reporting capabilities and have the ability to reach and share information within their sectors, between sectors, and among government and private sector stakeholders.” (Source: Presidential Decision Directive 63, 1998).
Source: Starting Point: U.S. Election Systems as Critical Infrastructure, U.S. Election Assistance Commission, https://www.eac.gov/sites/default/files/eac_assets/1/6/starting_point_us_election_systems_as_Critical_Infrastructure.pdf