That the Liberals are considering lifting the "ban" on gay men donating blood shows just as much ignorance of (or contempt for) science as the Harper government. I'm guessing no one there remembers *why* Canadian Blood Services exists? I'm only alive because of (safe) blood transfusions, and I object to the Liberals meddling with the blood supply for political gain.
Blood is analysed before it is used, I can assure you that. Any hospital that blindly makes assumptions instead of practicing the scientific method and quality control practices, wouldn’t last long.
Banning a segment of the population from donating blood (because they want to help save lives) is fear mongering and discriminatory, full stop.