Environmental activists argue the Keystone XL pipeline would significantly worsen climate change. (AP Photo/Jacquelyn Martin)

When it comes to political hot potatoes, there may not be a better example than the Keystone XL oil pipeline. Since Canada-based TransCanada Corp. first proposed the pipeline in 2008, it has served as a litmus test for where President Obama stands on energy, economic and environmental issues. One of those latter issues is climate change, as environmental groups that oppose the pipeline argue that approving it would be bad news for the climate.

Whether the pipeline’s construction would significantly worsen climate change is hotly debated in Washington. But whatever the answer to that question, it may not matter as much as you think when it comes to where Americans stand on the pipeline. While environmental groups have made climate change a centerpiece of their argument against Keystone XL, it’s actually one of the least important factors driving opposition to the pipeline, a recent poll suggests.

[EPA: Cheap oil weakens the case for the Keystone XL pipeline]

The latest University of Texas Energy Poll finds that among Americans who have at least some familiarity with Keystone XL, 45 percent support the pipeline, while 21 percent oppose it. Not surprisingly, Republicans are strongly supportive, 72 percent to 7 percent, while Democrats overall are slightly opposed, 28 percent to 34 percent.

But here’s where it gets a bit more interesting: Why do people support or oppose the pipeline? Among Americans who are familiar with the pipeline and oppose it, the most common reason wasn’t climate change. In fact, climate change ranked sixth. Just 6 percent of opponents listed climate change as their main concern with the pipeline. Even among Democrats, for whom climate change is usually a higher priority, that figure rises to just 7 percent.

In contrast, some 34 percent cited environmental degradation as their main concern, followed by water contamination (16 percent), hazardous chemicals (10 percent), “benefits Canadian consumers at the expense of US consumers” (10 percent) and “propagates dependence on fossil fuels” (7 percent).

Some of those reasons, such as dependence on fossil fuels, overlap with climate change at least a bit. But the fact that climate change itself placed so low seems surprising, given that environmental groups have made climate change a prominent part of their opposition to Keystone XL.

Why do opponents in the general public diverge with environmental activists? It’s not immediately clear from these findings. But in general, opinion polls have found that climate change isn’t all that high on Americans’ priority lists. Other environment and energy issues, such as local pollution and energy prices, tend to get higher priority among Americans.

Maybe that’s because those issues tend to have consequences that are more immediate, direct and tangible. And, indeed, those types of issues tended to resonate in this poll among the pipeline’s supporters. When it comes to the “most appealing” aspect of the pipeline, supporters most commonly named “increases energy independence” (26 percent), “lowers energy prices” (25 percent) and “job creation” (25 percent). That being said, the project’s supporters in Congress and the energy industry have overstated these benefits at times.

[Fact Checker: Will Keystone XL pipeline create 42,000 ‘new’ jobs?]

Meanwhile, many people may view climate change as more distant and feel that most benefits of tackling it wouldn’t arrive for many years. Issues like that may not resonate as much with people as would more direct, immediate, tangible matters like our pocketbooks and the well-being of our local communities. And, indeed, this barrier to getting society to act on climate change is one of many that a growing body of psychological and social-science research has uncovered.

None of that means that getting the public on board with climate policy is a futile endeavor. But it certainly underscores the challenge policymakers and climate activists face in building momentum — even with a pipeline that activists have made a climate symbol.