Demonstrators hold signs in favor of a proposed pipeline, in Glendive, Mont., on Tuesday. Public hearings over a $7 billion Canadian oil pipeline have pitted supporters who crave jobs against critics who fear a spill would be an environmental disaster.

GLENDIVE, Mont. — The final days of rancorous public debate over a $7 billion oil pipeline that would snake from Canada through the midsection of the U.S. have taken on an unexpected urgency this week, as the economic and environmental stakes of the massive project snap into focus at a time of festering anxiety about the nation’s future.

The round of public hearings by the State Department — stretching along the proposed pipeline route from a community college gymnasium here on Tuesday in eastern Montana, through Nebraska and Oklahoma to the Texas Gulf Coast — is ostensibly meant to focus on a single question: Is the pipe in the national interest?

Addressing that question though — especially through the sprawling sweep of six huge states through which the pipeline or its pump stations would run like a spine — takes in a universe of conflicting, interlocking issues, from short-term economics to global climate, from the discontent of a rural belt losing population to issues of national energy security, joblessness, corporate power and prices at the corner pump.

Many of the hundreds of people who have come to the meetings — one Thursday night in remote Atkinson, Neb., is expected to double the town’s population of about 1,200 — said they felt they were making a kind of last stand.

“We need the jobs, it’s that simple,” said Bret Marshall, 53, a laborer’s union worker who said he hoped to get work on the line and drove more than 700 miles across Montana to be here for Tuesday night’s hearing.

Environmental impact

The State Department concluded last month that the project, Keystone XL, would cause minimal environmental impact if it is operated according to regulations, and the operator, TransCanada, has said the nearly 2,000-mile line would create 20,000 jobs in the U.S. Opposition groups around the country, though, said the federal study did not consider the effects of a major spill, while supporters said the nation’s economy has continued to worsen, making Keystone XL all the more crucial.

The politics has fractured along unexpected lines. Here in Montana, Gov. Brian Schweitzer, a Democrat, strongly supports the project, while in Nebraska, Gov. Dave Heineman, a Republican, and both U.S. senators, one a Democrat, the other a Republican, have called for the line to be rerouted because of concerns about the Ogallala Aquifer, a crucial water source beneath the Great Plains.

The public meetings, which end this week, also come on the heels of a summer’s worth of anti-Keystone XL protests in front of the White House, which led to the arrests of more than 1,000 people.

Groups like the National Wildlife Federation, while conceding that the Obama administration seemed to be leaning toward approval, gathered local organizations to speak out this week — from conservationists to ranchers — hoping their impassioned concerns would give Washington pause. The State Department is expected to decide by year’s end whether to give the project its final approval.

“The whole policy debate has dramatically increased in stature from a year ago,” said Anthony Swift, a policy analyst for the Natural Resources Defense Council, which is against the pipeline. “People would not be protesting, let alone getting arrested, for something that is a foregone conclusion.”

In Nebraska, controversy over Keystone XL has even managed to envelop the state’s beloved college football team.

Earlier this month, the University of Nebraska’s athletic director, Tom Osborne, who is a former Republican congressman, pulled TransCanada’s sponsorship of a video that ran on big screens during two home games. The video paid homage to a former Cornhusker offensive line known as “the Pipeline,” and featured TransCanada’s logo.

Osborne said the athletic department took no position on Keystone XL, but sought to avoid political advertisements. “Over the last two or three months, the pipeline issue has been increasingly politicized,” he said in a statement.

One of the main contentions expressed by Keystone XL’s opponents this week is that a pipeline of this size and scope is simply too risky to operate.

Oil of the sands

Keystone XL will carry a coarse mixture that includes bitumen drawn from the oil sands of Alberta. Environmental groups have long contended that oil sands crude is more corrosive to pipelines and more difficult to clean when spilled. Oil sands, harder to extract and refine, they say, will also put more carbon in the air, accelerating climate change.

A TransCanada spokesman, Terry Cunha, pointed out that the company had agreed to adhere to 57 special conditions outlined in the State Department study to keep the pipeline especially secure. Cunha said that Keystone XL would be built with thicker material in especially sensitive regions — called “high-consequence areas” in federal regulations — and monitored with thousands of sensors, making it, he said, the safest pipeline in North America.

“We believe it is important that the decision on this presidential permit is based on facts and not on the mistruths that many of these groups continue to share,” Cunha said.

But some pipeline safety experts and environmentalists said that lax regulations and a raft of recent oil spills had raised concerns that the tiny federal agency overseeing the nation’s network of pipelines, the Pipeline and Hazardous Materials Safety Administration, may be unable to handle a project of Keystone’s magnitude.

And people in rural areas like eastern Montana say they also know that the dry and mostly empty ranchlands where they live, they are not, and never have been, places of high consequence.

“Nobody wants to be told they’re of low consequence,” said Tim Hess, 65, a wheat farmer and cattle rancher born and raised here in Montana who would have about 1.5 miles of pipe cross his land but still did not know how much he would be paid for it.

Keystone XL’s opponents also point to a Enbridge Energy spill of 843,000 gallons of oil sands crude near Marshall, Mich., as an example of what can go wrong.

A little over a year after the spill, a 35-mile stretch of the Kalamazoo River remains closed. And just this week, Enbridge stated in federal filings that the cost associated with the spill, originally estimated at $585 million, might now increase by 20 percent.

Pipeline supporters at the public hearings, though, have hammered two main points over and over — that America desperately needs jobs, and that the oil would be coming from a friendly nation. The Keystone pipeline would also allow oil from new fields in the Dakotas, Montana and elsewhere to be shipped south to Texas refineries, boosting the local economic appeal.

“All I ask is that you treat the 50,000 people in these six counties with respect and dignity,” Glendive’s mayor, Jerry Jimison, said Tuesday in comments that supported the pipeline but also hinted at a veiled threat. “That will affect the long-term relationship into the future,” he said.