As a former head of the U.S. State Department, there probably are some questions that Hillary Clinton ought not answer as a political candidate, because her opinions could prejudice some operation. Perhaps there could also be legal ramifications for some issue at State that is now in the courts.

But does anyone think that the endlessly discussed Keystone XL pipeline project imposes some ultrasensitive cone of silence upon candidate Clinton?

Clinton dodged for the second time in a week when asked her opinion of the project.

The excuse is that there is yet another review of the project at State, so it would be inappropriate for Clinton to comment before Secretary John Kerry announces the result of the study.

“I’m in a different position than any other candidate. I was there,” Clinton later told reporters after declining to answer voters’ questions on the project in New Hampshire. “I put this process together. I oversaw it for four years. I know what the president’s standard is to make sure it does not increase greenhouse gas emission. And I would slightly disagree with you — there has been additional research and investigation done since I left that I’m not privy to.”

“So that’s where I’m leaving it,” Clinton says, but we are not persuaded.

Democrats in the oil-producing states have tended to back the pipeline project, but most environmentalists are opposed. President Barack Obama has pushed the seemingly endless studies, although the State Department’s initial review concluded that the Canadian oil will be refined somewhere else.

Realistically, that means there is no great net increase in greenhouse gas emissions.

Why is the State Department even involved again in this issue? Its approval is needed because the pipeline crosses an international border. But that technicality of law — it’s not as though we are on unfriendly terms with Canada — has been used by Obama to delay a construction project that would provide many jobs and generate new products in refineries, probably in both Texas and Louisiana.

Either Chinese tankers will carry the oil to that country, or a safer pipeline will allow 800,000 barrels a day to be transported to refiners. If refined in China, where environmental standards are lax, the emissions from this oil are apt to be greater than if it is used in American refineries.

By dodging a perfectly legitimate question, Clinton is not being punctilious but instead adding to a reputation for political shiftiness.