Meaning of INSURGENT
Pronunciation: in'surjunt
WordNet Dictionary
Definition: [n] a member of an irregular armed force that fights a stronger force by sabotage and harassment.
They seem to fit the bill as "insurgents", especially when they were simply regarded (and underestimated) as "resistence" in the early stages of the conflict.
They have clearly morphed into terrorists, by definition. Since they are not allied and categorically united with their fellow countrymen, it would seem a bit odd to label them patriots.
If a Sunni and a Shi'ite decide to blow one another up willingly, they are warring religious factions, IMO.
Meaning of TERRORIST
Pronunciation: 'terurist
WordNet Dictionary
Definition: [n] a radical who employs terror as a political weapon
[adj] characteristic of someone who employs terrorism (especially as a political weapon); "terrorist activity"
I do seem to recall a guy who employed fear as a political weapon...but his name escapes me at the moment.
Either way you cut it, blaming "the liberals" doesn't foster any useful debate.