Ken Cuccinelli is treading on very shaky ground.

Virginia’s attorney general, who also happens to be the Republican Party’s nominee in the race for the governor’s office, filed an appeal this week on behalf of the commonwealth, which earlier this year found itself on the wrong end of a judge’s ruling regarding a plan to levy tolls on the Midtown and Downtown tunnels and the Martin Luther King Jr. Freeway.

Portsmouth Circuit Court Judge James A. Cales Jr. has ruled the General Assembly abdicated its taxing authority by allowing the Virginia Department of Transportation to partner with a private company to set tolls for all three crossings that would pay for the company’s expansion of the Midtown tunnel.

The $2.1-billion deal would cost daily commuters about $1,000 a year starting in February, and the tolls would be in place for 58 years, with the company guaranteed annual profits that would ensure ever-rising costs to drive between Norfolk and Portsmouth.

In filing the appeal to Virginia’s Supreme Court, Cuccinelli is representing Gov. Bob McDonnell, whose administration pushed the partnership under the state’s controversial Public Private Partnership Transportation Act and refused to back down from it even in the face of overwhelming opposition from citizens of Hampton Roads and from many Hampton Roads lawmakers, including some fellow Republicans.

The crux of the appeal is the definition of a tax, and the simple irony of that statement should cause a shudder to run up the attorney general’s spine. It wasn’t so long ago that Cuccinelli made history by leading the charge in filing a federal suit seeking to have the Patient Protection and Affordable Care Act — Obamacare to its detractors — declared unconstitutional. The arguments in that case, too, centered on the definition of the word “tax.”

Cuccinelli’s current position regarding the tunnel project — that tolls are not taxes but user fees — is hard to reconcile with the position the plaintiffs urged the Supreme Court to take when they sued to overturn Obamacare. In deciding to uphold the new federal law, justices ruled the “penalties” were, in fact, taxes, which meant Congress had the constitutional right to levy them. The ruling was a blow to those conservatives — like Virginia’s attorney general — who espouse a desire to limit the government’s ability to dip into its citizens’ wallets.

Cuccinelli is in a tough spot regarding the tunnel project and its tolls. Secretary of Transportation Sean Connaughton has made it clear that overturning the tolls could cost the state (rather than just the toll-paying commuters) as much as the entire $2.1-billion cost of the project. But refusing to appeal the case would have been political dynamite for the attorney general during his closely contested bid for governor, as that refusal would have provided Democratic challenger Terry McAuliffe with excellent ammunition in Hampton Roads and across the state.

But for anyone who has been paying attention, Cuccinelli’s claim that tolls are not taxes comes across as hypocrisy, and hypocrisy makes a very weak foundation for a political campaign.