We’ve heard a lot about the Keystone pipeline these past few years — which, if approved, would carry oil from the tar sands of Alberta down to refineries in the Gulf Coast. Supporters say the pipeline will improve U.S. energy security. Environmentalists say the tar sands will prove disastrous for global warming.

That debate can get a bit abstract at times. And so, to make things more concrete, my colleague Steven Mufson decided to take a road trip last summer down the length of the proposed Keystone route, from Alberta to Texas.

He’s written the whole trip up in an excellent new e-book “Keystone XL: Down The Line.” The book is a fairly quick read and really offers a fascinatingly detailed look at many of the issues raised by the pipeline. It’s highly recommended for anyone interested in energy and environmental topics.

Here are seven interesting things about the Keystone XL pipeline I came across in the book — though keep in mind there’s a lot more in there:

It’s possible that public opinion is being influenced by courageous political leaders who are urging action on these issues, but the reverse is more likely. Most politicians have a keen sense for tipping points in public opinion, when, say, support for equal marriage rights or immigration reform becomes broad-based, and advocates become sufficiently organized and mobilized to make life hell for officials who won’t change their minds.

The exception is in the economic sphere, where public opinion seems beside the point.

Before January’s fiscal cliff deal, for example, at least 60 percent of Americans, in poll after poll, expressed strong support for raising taxes on incomes over $250,000. As you recall, though, the deal locked in the Bush tax cut for everyone earning up to $400,000.

Yes, legislative deals require compromise. But why is it that deals over economic policy almost always compromise away what a majority of Americans want?

This is typical of trauma centers, especially those in urban areas with more frequent gun violence, said Lynette Scherer, the chief of trauma and emergency medical services at the UC Davis Medical Center in northern California. Staffing costs are high as emergency medical technicians, nurses, radiologists, nurses, physicians, surgeons and others have to be on site 24 hours a day. Facility, equipment and supply costs add to the tab.

For a patient with a gunshot wound, a single surgery followed by two days in the intensive care unit runs about $100,000, she said.

A Republican National Committeeman in Michigan is facing criticism for posting on Facebook an anti-gay article. And now a group of Republicans in the state has called for his resignation from the RNC, the Detroit Free Press reported Thursday.

Dave Agema, who previously served as a Michigan state representative, posted an article Wednesday on Facebook that described the lifestyle of homosexuals as "filthy." It also listed "some statistics about the homosexual lifestyle," including: "Many homosexual sexual encounters occur while drunk, high on drugs, or in an orgy setting (7)," "50% of suicides can be attributed to homosexuals (10)" and "Homosexuals account for 3-4% of all gonorrhea cases, 60% of all syphilis cases, and 17% of all hospital admissions (other than for STDs) in the United States (5)."

A statement from the group of Republicans, according to the Free Press, said, “This isn’t about what we believe either politically or as women and men of faith. This is about common decency and realizing that you cannot win an election by insulting a wide swath of the electorate, whose votes our Republican Party needs to once again form a national majority.”

High school science teacher Tim McDaniel is being investigated by Idaho’s professional standards commission because he allegedly used the word “vagina” while teaching a 10th grade biology lesson on reproduction and anatomy.

According to a report from the Times-News, four parents complained to school officials after learning that McDaniel explained the biology of an orgasm and used the word “vagina” during a lesson on human reproduction in his sophomore science class.

A disciplinary letter from the Idaho State Department of Education also accused McDaniels of showing a video clip in class depicting an infection of genital herpes and teaching about different forms of birth control. The letter also alleges that McDaniels told inappropriate jokes in class.

McDaniel also found himself in hot water for asking his students to write a critical response paper on climate change after showing them “An Inconvenient Truth.”