Petroleum pipelines are built in easements, and don’t encumber the surface uses of the land.
Its a good use of eminent domain, and they usually pay well for the use of the land.
As a land owner I'll decide what is good use of my land, and not some politically connected private enterprise who can take it from me. I'll also decide what I want paid for the easement and blockage of access, and not the amount that some corporate hack decides to pay me.
A pipeline on my property not only decreases my market value, but has also requires an access easement, and raises the specter of potential property damage and harm. As the owner I want the right to decide on my own if I want that exposure, and not have a gang of beholden politicians in DC decide for me. Either Repubs are for eminent domain by private enterprise or they are against it. Now they are for it for Canadians in the USA.
When it is all said and done this Canadian oil is going to the highest bidder (probably commies in China), and not necessarily to the benefit of the USA. It is foreign oil, not USA oil. We get only a pittance from giving them access.