The Jaridan Coalition was a group that existed within the Romulan Star Empire.
A senatorial coalition, the Jaridan were the ruling coalition for a time and had the largest number of members as well as influence on the Senate. It was based on a strong support for the Romulan military by providing a constant influx of resources for the construction of new ships and recruitment as well as training of more military personnel. The Jaridan supported a policy of continued outward expansion of the Star Empire in order to follow the teachings of D'era. As a result, they often supported new campaigns to explore and conquer newly discovered planets as well as the ongoing policy of confrontation with the Empire's enemies such as the Federation and Klingon Empire. Thus, they believed that military support and a continued wave of expansion helped ensure economic prosperity as well as aided in the stability of the Star Empire.
This meant that they received support from the majority of the Romulan military and many of its members were often former military officers themselves. These individuals often retained ties to their former commands and had considerable military resources to draw upon. Neral often favored the Jaridan Coalition and was supported by them. (Last Unicorn RPG module: The Way of D'era: The Romulan Star Empire)