If there is a credible threat of retaliation (violence, employment, housing) for even trying to vote, then this is very effective. Why take a big risk if you w

If there is a credible threat of retaliation (violence, employment, housing) for even trying to vote, then this is very effective. Why take a big risk if you won’t get to vote anyway? This way you don’t actually have to give the test very often, everyone quickly figures out the “rules” and falls into line.