The latest forum for the national debate over abortion is whizzing by at 65 mph.

Anti-abortion groups have won approval in at least 18 states for specialized license plates with the tagline "Choose Life," even as officials in New Jersey and other states fight the requests on various grounds.

The cases raise unresolved questions about whether license plates — or even portions of them — convey government or private speech. To raise revenues, many states let drivers buy specialty plates that recognize everything from military units and colleges to sports teams and nonprofit groups.

"Legislatures can say there might be certain controversies they do not want discussed on license plates," Assistant New Jersey Attorney General Andrea Silkowitz argued Tuesday in the 3rd U.S. Circuit Court, referring to an Illinois case.

Silkowitz argued that her state rejected the "Choose Life" plate not to avoid controversy but because the relevant law limits designs to group names and logos, and does not permit slogans.

In 2003, the New Jersey Motor Vehicle Commission approved a request from the New York-based Children First Foundation, but later rejected the proposed design, which included a small graphic of a sun, two children's faces and the words "Choose Life."

The New Jersey agency also dismissed a later attempt to substitute a new domain name, "NJChoose-Life.Org," for the original "Fund-Adoption.Org" on the plate.