The term "Voter ID" is somewhat complicated as it can refer somewhat separately to two different eras and types of policy.

Historically, many states, municipalities, and etc. had instituted legislation or policy requiring that voters provide some form of identification, better referred to as "evidence of identity" to avoid confusion with the concept of a state ID, in order to register to vote. This was intended to deter fraudulent identification, but requirements are very lax. For example, my state has a voter ID law as does my municipality, but these are part of a "first wave" and are extremely lax. ID is required only once. Nearly any document bearing name and address and, in many cases, a simple sworn statement signed before an election official are sufficient. Voters who register to vote with a county clerk or certified voter registration agent are not required to provide ID at all, as completing the form before an election official is considered a sworn oath. In general, the only case in which a voter is required to show ID is if they register by mail and decline to provide a DL number or last four digits of SSN on the form. In such a case, they may show any suitable document the first time they vote and the requirement will be removed for all future elections. Election officials are trained to err on the side of accepting identification documents. Things like school report cards or phone bills are often used by people with less access to government services due to poverty or rural residence. The definition of "address" is even quite lax, for individuals living in rural areas, written directions or a drawn map depicting their residence are acceptable.

This is considered a "voter ID" law, but is fairly different in origin and burden on the voter than the modern sense of a "voter ID" law, which may be as strict as requiring a photo ID issued by the federal government or motor vehicle administrator at the polling place for all elections. Because requiring payment for such a document prior to voting would likely be considered an illegal poll tax, many jurisdictions with such laws have instituted something called a "voting-only identification card" or similar which can be obtained from the motor vehicle administrator with no fee. However, waiving the fee on applying for a motor vehicle administrator's 'state ID' is largely missing the point. The true burden that people with limited access to government services face is less the fee and more the difficulty of obtaining the evidence of citizenship required for these documents. For people who were born in an impoverished, rural, or otherwise challenging context may have significant difficulty and face significant expense in obtaining a birth certificate, or no such birth certificate may exist. Historically, alternate documents attesting to the context of birth (for example, issued by a Catholic diocese on baptism or by a sovereign indigenous nation as documentation of membership) have been accepted to handle these situations, but modern voter ID laws often exclude such alternate documents. Further, under federal policy evidence of birth is often not the only document, and other documents are required as well.

The summary is that there is, for the last decade or so, a "second wave" of voter ID laws which are more stringent and difficult to satisfy than nearly any historical identification scheme. In some cases obtaining a state voting-only ID is even more difficult in terms of documentation than obtaining a US passport, even aside the relatively high fee and long processing time for a passport. This is what leads to these laws being widely interpreted as intended to reduce access to the polls rather than to address fraud.

Further complicating matters, the Help America Vote Act of 2002 imposed federal-level voter ID requirements. However, the federal government is not able to "override" voting legislation put in place by the states, which are solely responsible for administering elections. The result is that in some states, such as this one, there are two simultaneous paths for voter registration: the "state form" and the "federal form." The federal form actually imposes stricter ID requirements than the state form. For reasons I am not entirely clear on, HAVA requirements are interpreted as applying to all by-mail registration, with the result that some voters have to choose between obtaining additional ID documents (such as an SSN) to register by mail, or traveling to a county seat or other location where voter registration agents are available, where they can register to vote without these documents. Fortunately, there has long been a good deal of effort in getting librarians and other "prominent members of the community" certified as voter registration agents to make this route more accessible - in addition to the political parties often having their volunteers certified so that they can conduct door-to-door campaigns and be available at community events, although of course they often do this in ways that leads to the resulting registration turnout being party-biased.

In addition to adding more friction for individuals legally entitled to vote to exercise that right, the situation is frankly just confusing, which creates a big window for disinformation that even discourages people from registering when they would have an easy time doing so.

Just adding slight confusion to the whole matter is the fact that, due to a long-running aversion to citizen ID programs, the responsibility of tracking and identifying citizens has been de facto imposed upon the social security administration and motor vehicle administrators (DMV, MVD, etc). This creates a lot of confusion among especially people with limited government access - is it possible to vote without having an SSN? without being able to drive?