Why are democrats so convinced the GOP has filibuster power when the RINO's are so plentiful?

It just doesn't equate as you mentioned there are Rinos who side with the democrats nearly all of the time, Snow is a filibuster ending shoe in, and a party that enjoys that sort of a majority and holds the white house yet can not p its agenda, speaks loudly of its being an epic failure in my opinion! Perhaps they are more ready to blame others than accept their own failures or in Nov run on their own record, now that to me makes sense as far as their lack of reasoning goes.