What is with these attempts to inform voters on the ballot which politicians didn't support term limits? I know this also was tried in Montana, too.
State-imposed term limits on federal representatives and senators violate the US Constitution. The ballot labelling laws were an attempt to circumvent this limitation. The states argued that this was no different than provisions in state law that permitted a candidate for Congress to be designated by political party on the ballot (eg it was only information). But since there wasn't other information included on the ballot, and the clear intent was to get around the constitutional limitation, it has been ruled that it was equivalent to imposing a qualification.