The Obama administration has rejected the application from TransCanada to build the Keystone XL pipeline—but without fanfare. If President Obama continues to quiet the issue when so many others are raising its volume level, he will miss a grand political opportunity for his reelection campaign and the U.S. environmental movement. Public policy concerns of such inherent symbolism come once in a generation.

The debate over federal approval of the Keystone XL pipeline includes every flash point in 21st century environmental policy: water scarcity, sustainable agriculture, oil price inflation, job creation, property rights, and climate change. Many environmentalists have honed in on the proposed pipeline’s threats to water quality. As currently planned, the 1,700 mile long pipeline would travel through the Midwest’s Ogallala aquifer en route to Texas. A single leak could spoil the water supply for the country’s most prolific agricultural region. TransCanada and its political allies have targeted job creation in their public relations strategy. House Speaker John Boehner claims 20,000 jobs would be created by the project; former GOP presidential candidate Jon Huntsman claims a figure of 100,000. Fox News argues the pipeline “could provide up to a million new high-paying jobs.”

Now, in the wake of defeat, Boehner and other Republican leaders are mindful of the pipeline’s value as a campaign issue. They are pitching it as an imperative for economic recovery.

For his part, President Obama has taken notice of the public health implications of Keystone XL; in rejecting the pipeline bid he championed “the health and safety of the American people.” The president apparently sees nothing in the plans for Keystone XL that distinguishes it from the rest of the infrastructure the oil industry has installed from Alaska to New Orleans. President Obama has damped down the issue. He relegated the issue’s review to the State Department, although it deserves scrutiny from water scientists and other environmental experts, not just diplomats. When he announced the rejection of TransCanada’s pipeline, he ignored its implications for climate change—just as he did in November’s statement on it. As of yet, there are no plans to mention Keystone XL in the State of the Union.

But the White House and the environmental movement can benefit from the Keystone XL pipeline’s continued life as a public concern. President Obama should define the issue’s future before the rest of its stakeholders do. Keystone XL deserves salience for its political symbolism as well as its substantive implications; it is a rare natural resources concern that connects with Americans of all backgrounds. First, the gargantuan scale of the proposed transcontinental connector and its palpable physicality give it universal appeal as a visual. Its length would extend the entire height of the continental United States, from Montana to Texas. Second, the pipeline has patriotic reverberations. A path cut across the whole of America, whether a transcontinental railroad or an interstate highway or a vast pipeline, appeals to this instinct.

National leaders have been calling for large infrastructure projects since Alexander Hamilton called for the federal government to fund “internal improvements” for his fledgling nation. Third, building structures as an activity is a strong metaphor in public discourse. The famous cognitive linguist George Lakoff and coauthor Mark Johnson have documented, in Metaphors We Live By (1980), that Americans form many political arguments using “construction metaphors.” Examples abound: “Is that the foundation for your theory? The theory needs more support. The argument is shaky. We need some more facts or the argument will fall apart.”

Finally, the pipelines of this sort have two elements: oil and metal. A pipe of this length resembles a river of oil. It flows, as most rivers do, to a large body of water—the Gulf of Mexico. And rivers have immense symbolic importance to Christianity and other major religions around the world. They are also literary motifs, like in Joseph Conrad’s Heart of Darkness (1903). These symbolic qualities have raised the visibility of the Keystone XL pipeline over the last year. It is up to President Obama to exploit the populism of the anti-pipeline cause—the element of its symbolism that can help him win reelection and reinvigorate the environmental movement for the long term.

On the electoral campaign trail, the environmental cause has always struggled to overcome the perception planted by its detractors that it’s the daydream of a suite of elites. But the current pipeline pathway can ruin the family farmer—the very cultivator of the American dream and the founder of the first national populist movement—by poisoning the water table in the Midwest.

Rolling Stone reported in November on TransCanada’s purchase of right-of-way easements from farmers positioned along the pipeline route in Montana, South Dakota, and Nebraska. One such farmer, Randy Thompson, was offered $9,000 by the transmission company for a 100-year easement. Thompson rejected the deal. “They would be burying the pipeline right in my water supply,” he said. “Even a small spill or leak would ruin my land.” TransCanada has a poor record on oil spills. The company’s latest Keystone pipeline, which began production in summer 2010, has already seen twelve spills. One leaked 21,000 gallons of oil in North Dakota. Yet TransCanada markets Keystone XL as “the safest pipeline in the U.S.”

This pro-farmer populist argument can be a rallying point for the White House as it reaches out to independents and Republicans to build a winning coalition for November. The Keystone XL pipeline has already proved itself as a hell raiser; in November, it compelled 10,000 people to form a human chain around the White House in protest of its proposed construction. And probable GOP presidential nominee Mitt Romney, a multimillionaire with broad Wall Street backing, is vulnerable to populist attacks.

For precedent on how to fuse environmental advocacy with populist rhetoric, President Obama can look to the legacy of Theodore Roosevelt. Douglas Brinkley’s recent book on Roosevelt, The Wilderness Warrior: Theodore Roosevelt and the Crusade for America (2009), details how the Republican president persuaded America to join his crusade for wilderness conservation. “I can no more explain why I like natural history,” Roosevelt said, “than why I like California canned peaches.” He linked the spirit of conservation with nationalism. He also linked his cause with populism; for Roosevelt, the best value of federal parks was their “essential democracy,” to be enjoyed by “people as a whole.”

Roosevelt also had experience challenging the oil pipeline business. His administration sued John D. Rockefeller’s Standard Oil, which by 1900 controlled access to 90 percent of the refined oil in the United States. The victorious suit resulted in the breakup of the massive organization into over thirty smaller firms. President Obama has already been studying Roosevelt’s economy theory; he based his December speech in Kansas on the trust-buster’s rhetoric.

The Keystone XL pipeline debate can also be an ideological resource for environmental organizers outside the White House as they sell the hazards of conventional energy for years to come. Environmentalists clamor and pray for issues as symbolic as this pipeline. It was decades before conservationists and biologists discovered the value of humpback whales, tigers, and pandas as icons for the wildlife preservation movement. Conservationists still hunt for a way to advertise the importance of invertebrates to global ecology.

Until the Keystone XL pipeline is built, TransCanada and its allies will redouble their efforts to elevate the issue’s profile nationally. The White House should act with the same passion. They should recognize the benefits of giving the pipeline a full hearing on the national stage. They may never see an environmental issue so rich in symbolism again.