That’s not really true. Islamists are the best organized and funded group, that’s why they are in good position. Other groups (like students, middle-class people who are just angry about food prices etc) are not organized. Besides, they don’t have guns. Islamists do.
In Lebanon, Iran has been funding Hezbollah which provides money to the poor Shias. This made Shias loyal to Hezbollah. Sunnis, Christians and other groups are majority, though many have been emigrating out of Lebanon (because of Hezhollah presence and influense). These other groups hate Hezbollah. Without Iranian money, Hezbollah would have nothing and would not be able to be “state within a state”.