> if a voter ID is free and requires no effort on the citizens part
That alone is a big "if". Getting an ID rarely requires no effort. But the bigger question above all that is why do it anyway? Why do anything to make it harder to vote? There is little to no evidence of voter fraud taking place in the UK (or US for that matter), certainly never on a scale that would come close to affecting the outcome of an election. Every time the number of people who would be unable to vote (even just because they've lost their ID) eclipses the number of fraudulent votes that would supposedly be caught.
That alone is a big "if". Getting an ID rarely requires no effort. But the bigger question above all that is why do it anyway? Why do anything to make it harder to vote? There is little to no evidence of voter fraud taking place in the UK (or US for that matter), certainly never on a scale that would come close to affecting the outcome of an election. Every time the number of people who would be unable to vote (even just because they've lost their ID) eclipses the number of fraudulent votes that would supposedly be caught.