The license plates are an icon of the tea party movement and carry a picture of the Gadsden Flag, reading "Don't Tread on Me."
And if Rep. Gary Ackerman, D-N.Y., has his way, political messages from either the right or the left, won't "tread" on state license plates.
Ackerman has crafted legislation that would curb 15 percent of a state's federal highway dollars unless they drop the politically-tinged plates.
In particular, Ackerman called out the Arizona state legislature which recently passed a bill calling for a specialized tea party plate, complete with the Gadsden flag.
The Arizona tea party plates cost $25. And $17 of that fee goes toward a panel that promotes "tea party governing principles."
That drew Ackerman's ire.
"License plates shouldn't be used as political payoffs," said Ackerman in a statement. "The Arizona GOP might think differently if the legislation were to create a MoveOn.org license plate."
But Ackerman's bill poses an interesting First Amendment issue: which plates "count" as political speech? For instance, Maryland has "Save the Bay" plates, in reference to the Chesapeake Bay. Virginia has plates which simply read "Kids," scribbled in a child's script. There are questions as to whether those messages constitute political speech.
Lawmakers have held federal highway funds hostage for years over a litany of issues, ranging from speed limits to seatbelt laws to the legal drinking age.
In particular, Ackerman's measure slashes state money from three federal highway programs.