Currently, states waste a lot of money buying junk & barely-functional software from private companies
These private companies end up being part of corporate capture (it’s in their best interest to have governments buy their products), thus creating a nasty cycle of lobbyists who try to push out competition
As most states need the same functionality/software, it could be done centrally - states could then choose whether they want to pay a private company, or use the publicly available software maintained & operated by this department - all open-sourced
State & city governments would effectively be clients of this department
This department would also help advising the federal government on technology, as it would be a pool of experts