"To lead the coalition" means to take charge and guide a group of people or organizations who have joined together for a common purpose or goal. Full definition
The focus is on leading a coalition of participating organizations in efforts to change the systemic issues in pet homelessness and pet overpopulation. (charitynavigator.org)
Not the Conservative - led Coalition government if recent reports prove today to be true. (conservativehome.blogs.com)
This is the dilemma facing affluent white liberals: They want to lead a coalition in favor of equality, but their identity places them under suspicion. (firstthings.com)