BROOKFIELD — A group of insurgent Republicans who failed to wrest control of the Town Committee at a party caucus have forced a primary, allowing voters to decide who gets to run the party. Some Republicans challenging the caucus winners, including Jim Vulcano, argue that the incumbent leadership was responsible for the party’s overwhelming defeat in the November municipal elections but have resisted their call for change. There were a lot of Republicans that voted for a Democrat based on the fact that they were frustrated with how things were being handled by the RTC.