I'm an extreme leftist liberal and I personally am not upset with this. I don't think a pipeline will destroy ecology more than expanding cities, mining, or building dams will. I also don't think it would be damaging to the NA people so long as the pipeline is underground in an inactive area (avoid burial grounds, trails, resources, etc) even though it'd be best if the NA land was not disturbed at all.

I think this could make the US less dependent on Middle Eastern oil, which would stabilize American oil prices. It's also extremely beneficial to the Canadian economy, because their currency is somewhat pegged to their oil.

The downside is pollution, but a modern pipeline is less likely to cause a spill than a boat or a train. It's not like this will cause any more oil to be used. While we SHOULD be focusing all our energy on solar since it is now cheaper, at least oil isn't as destructive to the Earth as coal (by mining) and doesn't hurt the atmosphere as much.

I dunno, if I'm overlooking anything please point it out to me. The only thing that's upset me about Trump so far is removing LGBT and climate change mentions from the White House website, but at least he's not seriously going forward with the wall and forced documentation of Muslims... :(