This really isn't an issue that should be politicized. People need blood for transfusions. There's a risk that the blood will contain blood-born infectious diseases. You can test the blood but there's a risk that the test will deliver a false negative. Therefore no matter what you do there's a risk of being exposed to contaminated blood through transfusion. The only consideration that should come from this is how do you ensure the safest supply possible while still ensuring that there is enough blood for transfusions. It's not a fundamental human right to donate blood.