The Democratic governor of Missouri, Jay Nixon, announced this week that he favors construction of the Keystone XL pipeline to bring crude from the Canadian oil sands and our own Bakken shale region to refineries along the Gulf Coast.

At first glance, the relevance of Gov. Nixon’s opinion might not seem immediately apparent.  Keystone XL won’t actually pass through Missouri.  But it turns out there’s a very good reason people should listen to the governor of the Show Me State.

That’s because the original Keystone pipeline, which brings crude from Canada to refineries in Illinois, traverses the northern half of Missouri. So the governor and his constituents have real experience dealing with a pipeline from the Canadian oil sands. By and large, their experience has been a good one.

Gov. Nixon’s letter to Secretary of State John Kerry about Keystone XL is worth reading in its entirety. I want to highlight one point in particular:

It has been our experience that with vigorous review and oversight, projects like the proposed Keystone XL pipeline can be constructed and operated without jeopardizing public health or the environment.

The governor noted that even though the Keystone pipeline is buried and largely unseen, its positive impact is strongly felt by his constituents: The pipeline annually generates millions of dollars in property taxes in the 10 Missouri counties through which it passes.

Keystone has had “a positive impact on our state’s economy during my administration,” he wrote. “It is my belief that the proposed Keystone XL pipeline would yield similarly positive results for our country.”

That positive experience helps explain why Missouri officials are working with Canadian company Enbridge to construct a similar pipeline that will pass through Missouri to connect Illinois to the oil hub in Cushing, OK.

On Tuesday The Denver Post editorialized in favor of going ahead with Keystone XL. “The federal decision on whether to approve the pipeline isn’t supposed to be about politics,” the editorial board wrote. “It’s supposed to be based on the relevant facts, which in recent months have tilted heavily in favor of construction.” This refers to the State Department’s conclusion in January that the pipeline would not substantially worsen greenhouse gas emissions, not to mention the five years of thorough study that has gone into this project.

Thanks to Missouri Gov. Nixon, we are reminded that Keystone XL has strong and well-informed leaders from both sides of the aisle calling for the project to move forward.

The question is: What is the Obama administration waiting for?