I haven't rewatched the episode yet, but I thought he said something along the lines of "us benders." Something similar. I got the impression that he was trying to unite them in favor of his idea because "us benders" weren't safe.
Tarrlok could have easily just been referring to himself, Tenzin, and the Fire Nation councilwoman, since the Equalists are a threat to them specifically, and even if the Earth Kingdom and Southern Water Tribe councilmen are non-benders, "us benders" still make up the majority of the city council. It could go either way, really, but I don't think a government half-formed by Aang would be so biased as to not have any non-benders in the highest offices. After all, half of the Four Nations are traditionally ruled by non-benders anyway.
The idea of benders overall as too dangerous to nonbenders may not have had a hold on people at that time, but we didn't see that bending versus nonbending explored in how it manifested in culture. Having Sokka feel insecure because he couldn't bend or calling it magic doesn't count; nor do Ty Lee and Mai being competent while not bending.
We still got to see a lot of everyday goings-on in the three remaining nations, and bending prejudice was never really an issue for anyone. It might have been a thing in the Fire Nation, but the Fire Nation's culture at the time rewarded bullying anyway, whether it involved Firebending or not. I'm still more inclined to believe that the prejudice is relatively new and specific to Republic City.
I think the war can be used well to support the movement, regardless of it being firebenders who started it. Yes it could have ended up into an antifirebender movement instead, but it didn't have too. History doesn't work that neatly.
Just because it's easy for hate and prejudice to become widespread doesn't mean that this particular development of prejudice makes perfect sense. The Fire Nation was clearly responsible for the war, and it was always the Fire Nation against either the Earth Kingdom, the Water Tribe, or both.
I think they've just done a poor job of explaining the genesis of the prejudice thus far. If they had shown us that the fear of Firebenders came from the Republic Citizens from the Earth Kingdom and the Water Tribes and the fear of Earth and Waterbenders came from those from the Fire Nation, it would be a little easier to believe. Instead we just suddenly have extremist terrorists like the Equalists and pompous loons like the park protester suddenly giving all benders the stink-eye and going "Grr, benders bad! Normals good!" despite nearly a thousand years of history showing benders and non-benders coexisting without it being an issue.