The issue started with the initial render texture, so all the other passes compounded the problem. I narrowed it down by displaying that first render texture as if it was the last "composite" texture. Let me say it another way: When I was trying to find the problem, I took out EVERYTHING except the first render texture and ONLY displayed it by rendering it as a sprite to the backbuffer.
Rendering the image as a sprite has no blending because the image has an alpha of 1.0...... Not to mention, the issue wasn't present in the rest of the image, just the quads that had the transparency. When I render all the objects(including the transparent ones) to a texture, blending occurs where appropriate. After that, the objects are no longer rendered-- it's just a texture that I apply to a quad.