The government just can't seem to resist getting all possible identification tangents from its citizens, for the obvious reason that a National ID card which is in essence, what the Real ID law sets up, has huge benefits for the Federal government, in being able to monitor all, and to treat all as subjects that should be subject to the constant eye of the federal government in all that they do. The Real ID act was passed in 2005, and while the law is rather lengthy, it can be summed up into the basic premise that instead of each individual State having the right to create their own driver license's in the manner that best fits their desire and budget, they must instead, adhere to the format of such as dictated by the National Government.
At the present time, States that do not desire to adhere to the Real ID law, can subvert it or avoid it or request an extension to it, but in all things involving the federal government, this isn't a game that States are well positioned to play successfully with the very entity that can both bestow federal funding and largess for necessary things that States' desire and need, or to withhold such and thereby penalize the State. When it comes to money, and really all States want their fair share, the federal government holds the purse, and He who holds the purse, wields incredible power.
The main features of the Real ID act is that the database and security features of State issued identification cards would be compatible State to State, meaning that all fifty States would have the ability to read State IDs from any of the fifty States as well as the federal government maintaining and managing the entire database. Additionally, these State IDs would be machine readable, signifying that these machines would be able to read all "actionable" information on a State-issued ID, of which the owner of such, would be blithely unaware of exactly how personal and how detailed that information would be. All of this combined, would create a database that ultimately wouldn't be controlled on a State-to-State basis, but on the National level, in which, the Federal government, would know for a certainty where each individual lived, worked, traveled to, and when and where documents were provided to identification depots.
Of course, as always, this government, insists these things are necessary for the safety and security of the nation, which, has its place, especially if this National government considers itself to be the shepherds, and we the people, to be its dim-witted sheep. As invasive as the Real ID act is, this National government will invariably want even more and that final piece of the puzzle, would be to add onto our future driver license's a Radio Frequency Identification (RFID) tag, which, as these tools get even more sophisticated and powerful, would allow the government to know in real time, which streets we walk upon, which streets we travel upon, and who exactly we are, where we are going, what we are doing, so as to monitor us in totality 24/7, every day in every way, till we depart this cruel world.