From "moderate" to "mainstream": what is the difference, alas?

"An alliance of mainstream rebels who are backed by President Bashar al-Assad's Arab and Western foes said they had taken Bosra and declared the start of a new attack against government forces in another area of Deraa province to the northwest. The spokesman for the Southern Front alliance said 85 percent of the fighters who took part in the attack were from mainstream rebel groups, with the rest from Islamist factions." (thanks Basim)