Since 2003 a number of states have passed laws requiring some sort of ID to be shown when a person goes to vote. Proponents of the laws present them as a way to stamp out voter fraud; opponents decry the laws as a way to prevent minorities or the poor from voting, as they are most likely to not have acceptable ID. The battles have waged not only in legislatures but in courthouses as well. Wisconsin’s law was just struck down by a judge and Texas’ law is being challenged by the DOJ.
For a libertarian, it seems like both sides of the argument have been a little disingenuous. Voter fraud has yet to be shown to be anywhere near as widespread as Republicans would like us to think, though this could be because it has heretofore gone undetected. And showing a form of basic ID, often provided at no cost to the voter, is a very low bar and one that is gladly accepted when doing numerous other activities - even buying alcohol or getting into a bar.
So we are left to sit outside and try to figure out which side to take. On one hand, for those libertarians who believe in voting, the integrity of elections is very important. We need to ensure that elections accurately represent the will of voters. On the other hand, though, it is important that no one is prevented from voting for illegitimate reasons. If the laws are an underhanded attempt to disenfranchise certain groups, as opponents say, they are problematic.