It isn’t like the construction of a petroleum pipeline is going to somehow create a brand-new situation as to whether pipelines in general are either safe or dangerous. Consider the number of pipelines already in existence throughout the US AND Canada, and show their safety record in relation to movement by oil tank railroad car or 18-wheel tank trucks over the highway.
And it isn’t even whether the production of oil from “oil sands” is particularly more or less “dirty” than other forms of extraction. That is just dung thrown up by people who have no knowledge or experience around oilfields of any kind. Oil extraction is messy business, to be sure, but the safeguards built up over the years have managed to contain the “brownfields” created from going beyond the given perimeter, if the control of that perimeter is left up to the producers.
It’s about crony capitalism, using the force of government police power to come to the economic benefit of a small number of people. A benefit that does not translate into marketing efficiency.